Memory Foam Office Chair Cushion Car Seat Pillow Coccyx Orthopedic Pain Relief Features As per recent studies the most common cause of low back pain is postural stress. According to a leading university's Department of Ergonomics, up to 90 percent more pressure is put on your back when you sit versus when you stand. There are several reasons why, the first being that if you're like most Americans, you habitually sit in ways that cause tension and imbalance in your back and neck. This applies to sitting at work, in the car, and at home. WHY VITEPS SEAT CUSHION Ergonomic design seat cushion with U cut contour for proper spine for relief from coccyx,, tail bone and lower back pain. quality chair cushion, Memory Foam , 2.7inch thick and measuring 15.7 x 15.7 inch. Portable foam cushion is easy to carry along wherever you go and convert any hard into a seat Breathable, washable, removable fabric with zipper Product inclusion 1 x Portable foam cushion Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.