This bag could fit a comforter in it. It is hard to capture air in it as its so big. The fold lines from shipping also make the task difficult. Swinging the bag around captures enough air to fill it. One bag full should easily fill anyone's small air mattress. Definitely not for ultra light backpacking due to size and weight. It's a little too large/ackward to line my Osprey Exos 58. Great for car/boat camping though as you can store towels, blankets, clothes in it and use it as a big pillow. You could also put it in the bathtub and store water in it during an emergency. I should have gotten the smaller one for backpacking, but the great price on this larger one sucked me in.
This review was written in the old system and had content requirements that are different than reviews written today.