Donut Pillow Chair Seat Cushion, Memory Foam Firm Coccyx Pad Donut Cushion for Long Sitting, Office Chair, Gaming Chair and Car Seat Cushion - Black 17.5*18.5*5.5 inMemory Form Seat CushionThe doughnut cushion is made of high quality high density rebound memory foam, which provides strong support for the buttocks. Our coccyx cushion has a breathable mesh cover that doesn't trap heat, so you sit comfortable and cool. The donut seat cover is removable and machine washable Dount Seat CushionTwo humps hips curve U shaped cut out ergonomic design cushion help alleviate pain and provide the best comfort and support.