The Ergonomically designed and patented orthopedic foam waterproof seat cushion by Okwu Comfort will add the proper comfort to your chair, bench, car seat, plane seat, floor, or wheelchair. Designed by an Occupational therapists practitioner, the rear shaped cutout provides back pain relief by reducing pressure on the tailbone known as coccyx. Meanwhile, the ergonomically designed contour shape of the pillow promotes healthy weight distribution, posture, proper vertebra alignment, and superior comfort. Most importantly, it will not flatten out like other cushions because it uses the highest quality comfort foam for optimal support over long stretches of time. The waterproof cover is machine washable and can be removed using the zipper for easy cleaning. The cushion measures 18 x 16 x 3.75 inches.