I bought one this summer......hated it! I kept sliding off it, there was just too much air in it. Last week I took an Ice pick to the side of it and let out a bunch of air, had to do it twice to get it out....I was hoping it had a gel center, not just air. At any rate, at least now I can sit on it without feeling like I was going to tip off the chair. I'll try it this way and see how it goes.....but I feel like it's a giant waste of money. I'm going to look for the gel pads they sell for wheelchairs.