Ideal for balance, stretching, physical therapy, mobility, rehabilitation and core strength training. Waterproof mats that float which gives you the option to use in water therapy or water-based exercises. Aside from workouts, they can be used as a seat cushion for an extra layer of comfort. Lightweight, comfortable closed-cell foam that is easy to wipe clean. Ribbed pattern is molded into mat to resist rips and holes. Standard mats are 16 x 20 inches and 2½ inches deep.