Everest & Jennings Dura-Gel SPP Wheelchair Cushion, 4.5" Thick, 20x18", 8920208Brand: Graham Field Features: Reduces pressure points in critical zones with side wedges for lateral stability, a center pommel for thigh support, and a gentle slope for sit bone positioning and fall prevention 1st layer: medium density foam base 2nd layer: visco elastic gel core placed in 3 comfort zones to reduce tissue pressure at critical points 3rd layer: memory foam topper for supperior comfort and pressure relief Fluid proof stretch top cover