mesh polyester cover Fast rebound memory foam Immediate relief: Hemorrhoids, hip bursitis, coccyx fractures, herniated discs, bedsores, anal fissures, ischial tuberosities, coccyx fractures, stress related to childbirth, vaginal surgery, and prolonged sitting can cause lower back, buttocks, legs pain Ergonomically Designed Lifting Pad: Shaped like a doughnut with an ergonomic "U" cutout, our hip pillow conforms to the contours of the lower body for natural support with virtually no pressure on your most sensitive areas Firm and supportive foam core: The seat pillow may feel firm at first, but it's thermally reactive, meaning it softens once it absorbs heat from your body. Durable foam core retains its original shape even after prolonged use Key Features: Coccyx Pain Relief Pad is large enough to fit all 16" x 13" x 2.75". It's perfect for adults up to 240 pounds. The Sciatica Relief Pillow has a non-slip backing to prevent slipping. Our coccyx cushion features a breathable mesh cover that doesn't trap heat so you sit comfortably and cool. The donut seat cover is removable and machine washable Fits Most Chairs and Seats: This sitting donut pillow fits most office chairs, gaming chairs, office chairs, computer chairs, standard dining chairs, car driver seats, sofas, wheelchairs and recliners. A must have accessory if you work from home