The Vicair Adjuster X wheelchair cushion (see larger picture below) can generally be categorized as an air cushion due to its weight bearing air-filled cells. The manufacturer of this product, Vicair (in the USA - The Comfort Company is the source) specifies this cushion as follows.
Vicair's Adjuster X consists of a matrix of 8 individually adjustable chambers. Each chamber contains a user-changable quantity of permanently sealed tetrahedron-shaped air cells.
Vicair accomplishes the weight bearing function differently than other manufacturers of air cushions. The Vicair Adjuster X employs many small permanently sealed air filled cells, rather than larger valved air cells. Each of the many small Vicair air cells is shaped like a tetrahedron (a volume enclosed by four sides). The feel of the cushion can be adjusted by unzipping the liner and removing or adding an appropriate number of air cells. A pack of 50 extra air cells may be purchased with the cushion (refer to the cushion options above).
The Adjuster X's many-cell structure eliminates the leak-related catastrophic failure mode associated with other types of air cushions. The tetrahedron-shaped cell structure also slightly increases the user's seating stability as compared to typical valved-types of passive air cushions.
The X-series covers include Comfort-Tek and Stretch-Air, the Glidewear option being available for both covers. The Stretch-Air cover is the more breathable of the two covers, the Comfort-Tek cover being designed as an incontinence barrier. The Glidewear cover option can be applied to the top surface of the Comfort-Tek and Stretch-Air covers. Glidewear adds both a low-friction area on the rear of the cushion cover where bony prominences encounter shear forces, and a high-friction surface at the thigh areas and gluteal perimeter that helps keep the user from slipping into a sacral seated position (i.e, slumped with hips too far forward).
NOTE: Vicair Adjuster X cushions are made-to-order. The manufacturing process typically takes 4 business days. For example, if the "Fast" shipping method is selected for a Vicair Adjuster X, the actual transit time will indeed be fast (1-2 business days), but your cushion may be delayed by 4 business days before leaving the facility. Please consider these manufacturing times when selecting the shipping speed for Vicair cushions.