Muji (currently discontinued) cushion made of low-resilience urethane material. There is a faint stain on the part shown in the fourth photo. I washed the cover, but it didn't come off completely. It's faint, so I don't think it will bother you during normal use. Color: Gray Size: 36cm x 36cm, Thickness 2cm Material: Urethane, low-resilience material Due to high shipping costs, I am unable to offer a discount.