The bag is made of thicker nylon and has a heavy, stiff roll-top style opening with clips. The thick nylon material is stiff and is hard to fill with air, which requires more cycles to fill up the air mattress. Given that the sleeping pad is pretty heavy, not sure why this has to be as well. It could be a much thinner material, and not have a roll-top. This would allow it to be packable as part of the sleeping mat (in the same stuff sack, taking up much less room, and weighing less. I have an Amok Hammock sleeping pad that comes with an inflator bag that follows these principles, and it is a joy to use, weighs very little, and takes up next to no space.