Coccyx (tailbone) cutout reduces pressure on the tailbone and spine. Wedge angle encourages pelvic tilt to reduce pressure on lumbar discs and promote better posture. Designed for the car and also great for use in the home and office. Convenient carry strap for easy transport. Black faux suede is soft and durable. 100% polyester. Cover is removable. Hand wash in cold water, air dry only.