When lying on your side, place the cushion between your knees, in the manner which provides maximum support and relaxation. Duration of use varies according to individual needs. The composition is made of high resilience polyurethane foam (velva), designed to ensure stability of the cushion. With a comfort layer of high density, gel infused viscoelastic foam (memory foam) included. Easily carried or folded. Most Supportive for the knees/calves/ankles. Measures 09Wx22Lx03H. 3 Layered bamboo viscose removable cover is antibacterial, hypoallergenic and breathes/absorbs humidity. Machine washable in cold water. Lay flat to dry. No ironing. No bleach. Additional covers are available.