●Round, firm medium rebound type. The cushion has a non-slip backing so it stays in place even if you turn the chair at an angle ●Made with memory foam urethane that has a high resilience rate and is less likely to flatten ●It sinks to your body shape and balances body pressure. Less fatigue ●Since it is zippered, you can remove the cover by hand ●It is not too thin or too thick ●Size: Diameter 13.4 inches (34 cm), Thickness 1.4 inches (3.5 cm); Weight: 14.1 oz (400 g); Material: Polyester, urethane; Cord Length: 8.7 inches (22 cm); Cover Washing Instructions: Hand wash ●3 Month Product Warranty: We guarantee 3 months from the date of purchase. We only guarantee (replacement) in case of natural failure