Filling material memory foam.S code has a diameter of 30 cm and a thickness of 3 cm, M code has a diameter of 35 cm and a thickness of 3.5 cm, and L code has a diameter of 40 cm and a thickness of 4 cm.Sit and stand for long periods of timea good pillow, onepiece memory foam, can absorb the pressure of the human body, adjust the sitting position to a comfortable position, without strong rebound, soft and not collapsing, comfortable and natural.Strictly selected knitted cotton fabric, soft and skinfriendly, universal for all seasons, comfortable and breathable, not easy to pill and fade.Slow rebound memory foam, sitting on the mat, there is no pressure on the buttocks, and the material adjusts the pressure from irregular shapes to a balanced state, creating healthy circulation.