What will a Brain Bag hold?
If you have ever wondered here is what I had in mine. Three pairs of jeans, five T-shirts, one polo shirt, four pairs of socks and underwear, one pair of sweat shorts, misc toiletries which went in the pockets on the back. With all of that in it, it still fit in the overhead rack in a 737-900. My only complaint with the straps. I'm tall enough that I extend the straps almost all of the way to the end so the pack will sit low enough on my back to be comfortable. I wish there was a keeper or something to keep the strap from coming apart.