I bought two sets of eight in black and gray. One for my daughter's bed and one for my son's bed. Every time my son's dog would jump on his bed the bottom would move. These fully stopped that movement and now my floors are safe again. For my daughter's room I bought them for an entirely different reason. I needed to make sure her bed did not move. Low functioning autistic means she jumps on her bed and it will move, she doesn't watch where her feet goes and she hits the foot and it moves. I installed the gray on hers and had an extremely hard time moving her bed back in place. They work that well. There's no way that child is moving her bed around anymore. Where my son's bed legs were 1x2, I bought him the 2 in. There's a little left over but it did not stop them from working and they fit tightly at the 2-in mark. My daughter's bed feet are 2x2. If the bed feet are just a little over 2x2 like a millimeter over, they might still work but they are a tight fit And that is best. They were a bit of a pain to install but that's more because I had to do it by myself and lifting up a bed with one hand while installing these on the bottom of the feet, not an easy feat. The height of the outer casing, is minimal. They cannot really be seen unless you're looking for them. The thickness between inner edge and outer edge is also minimal but I think it's designed perfectly to create as minimal of a footprint as possible. The thickness does not add much height to the bed, no more than the thickness of the bottom of the pad. With my old hardwood floors not being even, I tried to install them on the metal support pole in the center of the platform bed and all but the middle, worked perfectly. But that's because of my uneven floors. It happens in a 70-year-old house. To push my daughter's bed back into place, was the hardest part. These things stick to that floor like you would not believe. I basically had to lift up and push hard. I know that bed's not going anywhere now. These are one of the greatest inventions ever and I am very impressed by this particular brand.