Size: 30*30 cm, 4.5 cm thick; 35*35 cm, 4.5 cm thick; 40*40 cm, 4.5 cm thick; 45*45 cm, 4.5 cm thick. Great as a gift! Material: Round seat cushions/chair cushion, PU leather fabric, waterproof, wear-resistant, dirt-resistant. Round seat cushion filled with high-density memory foam, moderate firmness, pressure-resistant, anti-deformation capacity; large objects can still bounce normally after being rolled over. Good anti-slip performance: The bottom of the round chair cushion is designed with anti-slip particles, so the cushion does not move or shift even on a smooth chair surface. Easy maintenance with zipper: The round seat cushion has a zipper on the side for easy maintenance and cleaning. Versatile: Round chair cushions are ideal for the dining room, office, living room, folding chairs, patio, or car seats. You can also use them as floor cushions, balcony cushions, bay window cushions, and tatami cushions.