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TLDR
With 30% more volume than the Synapse 19, the Synapse 25 is an everyday backpack designed with ultimate utility in mind.
- Main compartment with 2 O-rings
- Interior, banded open-top pocket
- 5 exterior front pockets with independent volume
- Comfortable, durable, edgeless shoulder straps
- Breathable back panel
- Removable sternum strap and waist strap
- Webbing loop on exterior bottom of bag to hook items on the outside
- Meets the personal item size requirement on most airlines
- Generally fits folks between 5'6" and 6'6" comfortably
02.
Full Description
Main Compartment
The main compartment closes with #10 YKK® Racquet-Coil zipper and is designed to fit large, flat items like notebooks. On the front interior side of the main compartment, there is a banded open-top pocket. It's spacious enough to fit a wide range of items, such as books, tablet, pair of sandals or our Clear 3D Organizer Cube. Above this open-top pocket is a set of Cache lops where you can secure a device as large as the 16" Macbook Pro in a Cache.
On the back interior side of the main compartment are an additional set of Cache loops and two O-rings for tethering additional pouches.
5 Front Exterior Organizational Pockets
The Synapse 25 has an abundant amount of organization for your everyday essentials, big and small. The exterior of the bag has five pockets with independent volume, meaning that the pockets are designed and patterned in such a way that they don't steal space from each other and they look good (not too caved in, not too bulgy) whether full or empty.
The water bottle pocket is intentionally centered in the bag, allowing one of the heavier objects in your bag to be balanced in the middle, resulting in a more comfortable carrying experience while maintaining a clean, straight-forward exterior aesthetic. We've found that most standard 32 oz / 1 liter water bottles can comfortably fit in the water bottle pocket.
Below the opening for the water bottle pocket is another small zippered pocket that is just deep enough for keys, a wallet, glove liners, or a small camera.
The side pockets are generously sized for sunglasses (in a case or alone), a first aid kit, or even a light Windbreaker-type jacket or down vest compressed in a Travel Stuff Sack. The right side pocket has a small organizational pocket; the left pocket has one pen slot and two wider slots for tools or more pens.
The bottom pocket is a great spot for extra clothing or snacks and will easily accommodate a thin sweater, light down jacket, or Windbreaker-type jacket. If you care to add organization, we recommend storing a Size 2 Handy Little Thing here.
Each of the top four pockets has its own O-ring, and the bottom pocket has three O-rings. You can use them to attach our mini or small Ghost Whale Organizer Pouches or Mystery Organizer Pouches.
Edgeless EV50 1/2" Shoulder Strap
Conformity is overrated — except, perhaps, when it comes to shoulder straps. The edgelessness of this strap allows it to more softly conform to your shoulder; we find that this increases comfort. Yet the straps aren't too soft: the 1/2" thick foam means the strap is robust enough to carry a heavy load.
There's enough length on the shoulder straps to accommodate a wide range of body types. If you need to tighten the straps to the maximum amount, don't worry about having dangling ends — we've included sewn-in strap keepers to help keep those at bay.
Breathable Back Panel
The back panel of the Synapse 25 is padded with 1/4", high quality, closed cell-foam with an exterior of Spacer mesh and 210 denier nylon. This combination of mesh and smooth nylon is designed to provide maximum breathability while still being gentle on your clothing.
Webbing Loop on Exterior Bottom
On the exterior bottom of the bag is a 1.5" / 38mm webbing loop. Originally, the Synapse was designed for hiking, so the intended use of the webbing loop was for hooking on a flashlight (highly recommended if you ride a bicycle or walk in the dark). If you're planning on using the Synapse for travel, we've found the webbing loop serves as an extra grab handle, allowing you to easily pull the Synapse from under the seat or the overhead compartment no matter which direction you stowed it on your flight.
What's Included
Included Removable Sternum Strap + Waist Strap
As with all of our major backpacks, we include adjustable and removable sternum and waist straps: if you don't like or don't use your waist or sternum strap, remove them!
8" Snaphook/Snaphook Key Strap
As with most of our bags, we've included a key strap. 8" long from tip-to-tip, a snaphook on either end. Good for attaching your keys to.
A Set of Black Zipper Pulls
A set of pulls to extend or replace your metal pulls.
What's Optional
Size 2 Handy Little Thing (HLT)
You can attach a Size 2 Handy Little Thing (HLT) to the pair of cache loops above the open-top pocket, or you can store the HLT in the bottom front pocket of the Synapse 25. It is the perfect clamshell organizer pouch for those looking for a lot of organization.
Packing Cube Shoulder Bag
The Packing Cube Shoulder Bag is the perfect 2-in-1 packing cube. It's big enough to store rolled up shirts. Once you reach your destination, attach a shoulder strap and use it as a crossbody.
Freudian Slip
Love organizing and want even more pockets? The Synapse 25/Synik 30 Freudian Slip adds an additional fifteen organizational pockets to your bag. One side of the Freudian Slip has two folder pockets that can fit folders/papers horizontally or vertically, as well as four open-top pockets for a small tablet in a Cache or a notebook. The other side has two mesh pockets for bulky items, two large zippered pockets, four pen slots, and a business card slot.
Cache
The Synapse 25 can accommodate a wide range of devices. If you plan on putting a laptop or smaller tablet in the interior banded open-top pocket, we recommend adding a Cache.
The main compartment closes with #10 YKK® Racquet-Coil zipper and is designed to fit large, flat items like notebooks. On the front interior side of the main compartment, there is a banded open-top pocket. It's spacious enough to fit a wide range of items, such as books, tablet, pair of sandals or our Clear 3D Organizer Cube. Above this open-top pocket is a set of Cache lops where you can secure a device as large as the 16" Macbook Pro in a Cache.
On the back interior side of the main compartment are an additional set of Cache loops and two O-rings for tethering additional pouches.
The Synapse 25 has an abundant amount of organization for your everyday essentials, big and small. The exterior of the bag has five pockets with independent volume, meaning that the pockets are designed and patterned in such a way that they don't steal space from each other and they look good (not too caved in, not too bulgy) whether full or empty.
The water bottle pocket is intentionally centered in the bag, allowing one of the heavier objects in your bag to be balanced in the middle, resulting in a more comfortable carrying experience while maintaining a clean, straight-forward exterior aesthetic. We've found that most standard 32 oz / 1 liter water bottles can comfortably fit in the water bottle pocket.
Below the opening for the water bottle pocket is another small zippered pocket that is just deep enough for keys, a wallet, glove liners, or a small camera.
The side pockets are generously sized for sunglasses (in a case or alone), a first aid kit, or even a light Windbreaker-type jacket or down vest compressed in a Travel Stuff Sack. The right side pocket has a small organizational pocket; the left pocket has one pen slot and two wider slots for tools or more pens.
The bottom pocket is a great spot for extra clothing or snacks and will easily accommodate a thin sweater, light down jacket, or Windbreaker-type jacket. If you care to add organization, we recommend storing a Size 2 Handy Little Thing here.
Each of the top four pockets has its own O-ring, and the bottom pocket has three O-rings. You can use them to attach our mini or small Ghost Whale Organizer Pouches or Mystery Organizer Pouches.
Conformity is overrated — except, perhaps, when it comes to shoulder straps. The edgelessness of this strap allows it to more softly conform to your shoulder; we find that this increases comfort. Yet the straps aren't too soft: the 1/2" thick foam means the strap is robust enough to carry a heavy load.
There's enough length on the shoulder straps to accommodate a wide range of body types. If you need to tighten the straps to the maximum amount, don't worry about having dangling ends — we've included sewn-in strap keepers to help keep those at bay.
The back panel of the Synapse 25 is padded with 1/4", high quality, closed cell-foam with an exterior of Spacer mesh and 210 denier nylon. This combination of mesh and smooth nylon is designed to provide maximum breathability while still being gentle on your clothing.
On the exterior bottom of the bag is a 1.5" / 38mm webbing loop. Originally, the Synapse was designed for hiking, so the intended use of the webbing loop was for hooking on a flashlight (highly recommended if you ride a bicycle or walk in the dark). If you're planning on using the Synapse for travel, we've found the webbing loop serves as an extra grab handle, allowing you to easily pull the Synapse from under the seat or the overhead compartment no matter which direction you stowed it on your flight.
Included Removable Sternum Strap + Waist Strap
As with all of our major backpacks, we include adjustable and removable sternum and waist straps: if you don't like or don't use your waist or sternum strap, remove them!
8" Snaphook/Snaphook Key Strap
As with most of our bags, we've included a key strap. 8" long from tip-to-tip, a snaphook on either end. Good for attaching your keys to.
A Set of Black Zipper Pulls
A set of pulls to extend or replace your metal pulls.
Size 2 Handy Little Thing (HLT)
You can attach a Size 2 Handy Little Thing (HLT) to the pair of cache loops above the open-top pocket, or you can store the HLT in the bottom front pocket of the Synapse 25. It is the perfect clamshell organizer pouch for those looking for a lot of organization.
Packing Cube Shoulder Bag
The Packing Cube Shoulder Bag is the perfect 2-in-1 packing cube. It's big enough to store rolled up shirts. Once you reach your destination, attach a shoulder strap and use it as a crossbody.
Freudian Slip
Love organizing and want even more pockets? The Synapse 25/Synik 30 Freudian Slip adds an additional fifteen organizational pockets to your bag. One side of the Freudian Slip has two folder pockets that can fit folders/papers horizontally or vertically, as well as four open-top pockets for a small tablet in a Cache or a notebook. The other side has two mesh pockets for bulky items, two large zippered pockets, four pen slots, and a business card slot.
Cache
The Synapse 25 can accommodate a wide range of devices. If you plan on putting a laptop or smaller tablet in the interior banded open-top pocket, we recommend adding a Cache.
Still Have Questions?
- emailus@tombihn.com
- Ask in our Forums
03.
Materials
Exterior
bluesign® and OEKO-TEX® certified Ultralight 400 denier Halcyon
— or —
bluesign® certified 630 denier High-Tenacity 2x2 Ballistic nylon
Interior
bluesign® and OEKO-TEX® certified 200 denier Halcyon/nylon ripstop
bluesign® certified 210 denier High-Tenacity 2x2 Ballistic nylon
Upper Back
Back Pad
Closed-cell foam
Shoulder Straps
Edgeless EV50 1/2” / 12mm shoulder straps (EVAZOTE® OEKO-TEX® foam)
04.
Specs
Dimensions
13.4" (w) x 20" (h) x 9.1" (d) / 340 (w) x 508 (h) x 230 (d) mm
Weight
400d Halcyon/420d nylon ripstop: 1 lb 13 oz / 822 grams
X-Pac®: 1 lb 13.1 oz / 825 grams
630d Ballistic: 1 lb 15.8 oz / 900 grams
Volume
25 liters / 1526 cubic inches (ASTM Standard Measure)
What's Included
1x 8-inch Black Webbing Snaphook/Snaphook Key Strap
1x Black Zipper Pulls w/ Plastic Ends (8-Pack)
1x Sternum Strap Assembly
1x Gatekeeper Waist Strap
Straps
.375" / 10 mm padded and contoured backpack straps with .75" / 20 mm removable sternum strap
Total O-Rings
9
(2 in the main compartment
1 in the top center pocket
1 in the small center pocket
3 in the bottom front pocket
1 in the left side pocket
1 in the right side pocket)
- Mason S.Verified BuyerBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Sewn in USA, Comfortable, VersatileYesterdayBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Sewn in USA, Comfortable, VersatileRated 5 out of 5 starsGreat Bag!
An absolute classic that delivers exactly what you need in a day and/or travel bag
Was this helpful? - richard s.Verified BuyerBought For MyselfProduct Standouts Good Storage Size, Versatile, Thoughtful Design, Comfortable, High Quality Craftsmanship3 days agoBought For MyselfProduct Standouts Good Storage Size, Versatile, Thoughtful Design, Comfortable, High Quality CraftsmanshipRated 5 out of 5 starsPerfect Travel Carry On
Kept me well organized and provided additional packing capacity on a recent 2 week trip to the UK
Was this helpful? - Ashleigh J.Verified BuyerBought For Myself1 week agoBought For MyselfRated 2 out of 5 starsMajor let down
I did SO much research into the perfect backpack, and was convinced that I was going to love this bag. I tried it out for over a month before this review and I'm definitely disappointed. First let me say that the quality of this bag is 10/10, its the design that makes it very bad functionally. The bottom of the bag is very narrow and it makes it very difficult to pack this bag out. For a 25L because of the way the pockets are, the pockets get overcrowded very easily and it seems like the bag really doesn't hold much at all. I bought this bag because of the organization but it turns out that the organization crowds the storage capability overall. I would not recommend spending so much money on this bag, it is really a let down. I wish I could return it but the tags are off of it. Definitely pass on this bag.
Was this helpful? - MJ L.Verified BuyerBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Comfortable, High Quality Finishings, Durable1 week agoBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Comfortable, High Quality Finishings, DurableRated 5 out of 5 starsFinally Got My 2025 Unicorn – and It’s Perfect
I saw this Black XPAC with Cerise interior combo a few years ago and totally fell for it—but missed the drop and was seriously bummed. So when it came back, I jumped on it fast, and honestly? It was so worth the wait.
The outside is super sleek and low-key—classic black XPAC that’s lightweight, durable, and weather-resistant. But then you open it up and boom—Cerise interior. Bright, bold, and super useful for finding stuff inside. It’s the perfect mix of stealth and fun.
The center water bottle pocket is a game changer—keeps everything balanced and doesn’t mess with the bag’s shape. And as always with Tom Bihn, the build quality and organization are top-tier.
This bag seriously nails it. It looks great, handles anything I throw at it, and finally getting this color combo feels like a 25L backpack dream come true!
Was this helpful? - Phillip S.Verified BuyerBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Easily Adjustable, Versatile, Comfortable3 weeks agoBought For MyselfProduct Standouts Thoughtful Design, High Quality Craftsmanship, Easily Adjustable, Versatile, ComfortableRated 5 out of 5 starsEverything I was told it would be.
After reading tons of Reddit thoughts on the Synik and the Synapse I decided on the Synapse. Very glad I did. You can tell there has been a lot of thought that has gone into this bag and the quality is second to none. I have a few USA made bags and this bag, in my collection, continues the quality. I look forward to years of carrying this bag.
Oh yeah, the black bag with pink inner is a very striking contrast and I’ve received a bunch of inquiries about it. All positive so far.
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05.
Sewn in Seattle
Our bags are designed and sewn right here in Seattle, Washington, U.S.A.
That allows us to be control freaks in the best way possible; we have direct control and oversight of the quality of our materials, our products, and the jobs and working environment that we help create. It also offers us a unique spontaneity: when we have an idea for a new product or accessory, we can design it, figure out how to build it, add it to our website and be ready to ship it out our front door all within just a few weeks. How cool is that?
Intrigued? You can find out more about the unusual way we do business on our Company Philosophy page.
06.
THE BIHN Guarantee
Everything you buy from us here at TOM BIHN is satisfaction guaranteed. We’ve been in business since 1972 and we stand behind what we make.
If something goes wrong and it's our fault, we'll fix it for free. Repairs due to normal wear and tear or due to other things that are not our fault will be performed, when possible, at a reasonable charge right here in our Seattle factory where your bag was made. Defects in materials or workmanship are uncommon and almost always evident while the product is still new. Keep in mind that bags and packs are often subject to extreme wear in everyday use: do not expect them to last forever. Only true love lasts forever! You can expect a TOM BIHN product to give years and years of hard service.