The Extreme Comfort General Use Wheelchair Back Cushion with Lumbar Support is perfect for patients who need additional support for their back or would just like extra comfort. The General Use Back Cushion uses a Durable Masonite board which is secured on the back of the unit and prevents swaying in sling back wheelchairs. The unit conforms to the lumbar curve which better supports the lower back. A sealed liner protects the foam core from moisture which will increase the life of the unit. The General Use Back Cushion's back is made of a special non-slip vinyl which prevents the unit from sliding when the use is moving. Cushion has two layers of foam, the base is made of a standard foam material, while the lumbar section is made of a high quality memory foam. 1 Count