https://www.ebay.com/sch/i.html?_nkw=Relax+Trio+Cushion+18X16X1+1+2+Inch&_sacat=0&_dmd=2

Relax Trio Cushion, 18X16X1-1/2 Inch

Regular price
$188.00
Sale price
$126.00

Relax Trio For medium risk. Four chambers of Flo-Gel with foam overlay conforms to the shape of the user, increasing surface area and relieving pressure. Equal chambers allow cushion to be rotated. Waterproof cover. No-slip base. Cover is breathable and stretchy to reduce shear force and friction. 180-lb. capacity. 1-1/2"H.