Drive Medical Canada 
Model # (16"×16"×2")8040-1
              (18"×16"×2")8040-2
Offering great versatility, the Gel-U-Seat™ Lite provides comfort to almost all wheelchair users
Unique dual-chambered gel bladder keeps the pelvis in contact with pressure redistributing cooling gel
The cover is fluid resistant low-shear nylon zippered and removable with a durable vinyl bottom
Secures easily to wheelchair with 12" tie straps
Meets flammability standard TB117
Cover material : 
Fluid-Resistant Stretch Top | Waterproof Vinyl Bottom
Weight Capacity : Up to 20" 275 lbs, 22" and up 500 lbs