Finally — a well designed, comfortable, and effective wedge cushion! Several things I deeply appreciate about this cushion. First, it works! I’ve been using mine for a little over a week and it’s making a noticeable difference in my sciatic pain. I’m beyond grateful. Second, unlike most wedge cushions, this one is designed so the back of your legs aren’t pressed into it. Third, it actually fits in my car seat so I can get the proper angle (knees below hips) when I drive. Fourth, it really is portable. Fifth, it’s fairly firm (the others I tried were too soft/squishy) without being uncomfortable. Sixth, it comes in 3 different wedge heights. I ordered the 2.5″ and just ordered a 3.25″ and a 4″ because different chairs have different angles. My back issues are degenerative, so this is part of my focus on postural correction to help minimize problems down the road. Thank you SITTS Perfect!!!