This large, medium-firm cushion is constructed of a highly resilient, furniture-graded foam with a layer of memory foam on top. This unique design combines the two key elements you are looking for: comfort and durability. It is firm enough to provide good support but not to the point of being "too hard" to undermine its use as a cushion. It can be used in the car, home, or office. It is designed to help relieve back pain, numb buttocks, and other discomfort associated with prolonged sitting. Cutout section suspends your tailbone (coccyx), reducing pressure on your lower lumbar discs. Wedge shape (slant from the back 3-1/2" down to 1-3/4" in the front) tilts your pelvis forward to restore your spine"s natural lumbar lordotic curve. What you get is a high quality product for a lot less than what you have to pay at specialty stores.