I'll post some pictures for size reference:
Ultraviolet Laundry Stuff Sack for A30 standing upright next to Steel Dyneema Pilot (on end) and French Blue Daylight Backpack with Steel Size 4 Travel Stuff Sack.
The Laundry Stuff Sack is a Cylinder that looks roughly like two Yarn Stuff Sacks placed end to end. (The sections are slightly smaller in diameter than a YSS, but that's the closest size). The next picture shows a top view with the center divider pushed all the way to one end. The "bottom" of the sack sits 2" or 50 mm below the end of the "cylinder" with a circular cross section.
Here's the ruler view of the depth:
The view from the other end of the cylinder shows the open sack, with a black piping circular border at the mid-point of the cylinder, and another circular border that marks the "bottom" of the sack that was shown in the previous view, now seen from the other side.
Here are some more size reference pictures with the Ultraviolet YSS at the right front, the Steel Small YSS in front center, and the Wasabi Size 3 Travel Stuff sack at front left. You can see the YSS is slightly bigger than each half section of the A30 Laundry Stuff Sack.
If you look closely at the first picture with the cylindrical UV Laundry Stuff Sack for the A30, you should be able to see that the top 2" section appears lighter. That's because the pushed in sack divider stops 2" from either end of the Laundry Stuff Sack Cylinder.