JARROD S. G The valve from your mattress fits snuggly into a Vinyl hole under the handle strap on the closed end of the sack. You then trap air in the sack by closing the large open end and then push the air into the mattress. It worked great when I used it, allowing me to fill my Neo Air XLite mattress quickly with just three sacks full of air, and then just a breath or two to fine tune.

ALEX W It comes with a coupler to connect it to the NeoAir valve.

HOWARD C There is a piece of clear vinyl about 1in square sewn into the center of the closed end of the bag. This piece has a hole in the center, through which the valve on the air mattress is inserted and forms a seal around the valve. Thus the air forced out of the pump bag goes into the air mattress. So, no, the pump bag doesn't have a valve but is designed to form a seal without a valve.