We love this bit of kit! The Neo-Air Pump Sack is such a nifty piece of design, just a big old dry bag with a valve shaped to inflate the Thermarest Neo Air (although it will fit many other inflatable roll mats). Simply attach, then start rolling it up to push all that trapped air into the mattress. It makes blowing up the new Neo-Air roll mat a job of seconds.
When you're done, you can use it as a pillow, a chair or just stuff it full of clothes.