General Use Extreme Comfort Wheelchair Back Cushion with Lumbar Support, 18" Pressure Redistribution Mattress Product Features Extends battery life Size:10 Ft Product Features Extends battery life of the Airsep Focus and Freestyle an additional four hours between recharges The seamless SoftEdge headgear reduces possible irritation from harsh edges 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 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