McKesson Foam / Gel Seat Cushion 18″Wx16″Dx2″H For Wheelchairs 170-73002. The McKesson foam and gel seat cushion for wheelchairs help in the avoiding, to treatment and management of pressure sores with enhanced pressure redistribution Its low-shear, stretchy black nylon cover is breathable to allow air to pass, but still resists fluids for lasting durability and easy maintenance Dimensions are 18 x 16 x 2 inches Open-cell, Visco memory foam offers breathability, while the gel acts as a cooling agent for temperature control and mitigating perspiration, allowing for comfort even over long periods of sitting Waterproof cushion comes with a hook-and-loop strap with a buckle, securing it to the wheelchair and limiting it from moving around