So this hot tub cushion is actually a pretty clever idea if you spend time in spas or hot tubs. It's made from PVC material that's heat-resistant, and it comes in different colors - pink, blue, black, or golden. The size is about 18.5x14.5x5.9 inches when inflated, which gives you a decent seating area. The cool thing is you can fill it with either air or water - there's a dual-purpose valve. If you use water, it adds weight and makes it more stable. It's got a mesh cover and suction cups on the bottom that really help keep it from sliding around, which is a common problem with tub seats. The suction cups are strong enough that the cushion stays put even when you're getting in and out. It works as a booster seat to raise you up higher in the water, which is great for kids or older adults who need that extra height. The PVC material is comfortable to sit on and easy to clean - just wipe it down. When you're done, you can deflate it and store it pretty flat. Definitely one of those simple products that actually makes using your hot tub or spa more comfortable, especially if you have back issues or just want to relax in a better position.