This is a 21.7 x 23.2 inches (55 x 59 cm) insert made specifically for the seat cover (Meisenji size). What’s the feature is 1) soft and 2) light. By the way, place this urethane on top of the folding or flooring and sitting on your butt is 2.4 inches (6 cm) thick, but it will change the feeling of the bottom. On the contrary, its softness is the "gour" of this product. Please refer to our product for reference. ★Sold as a set of 5.