The Vicair Twin O2 is a pressure cushion used in wheelchairs and static seating. Filled with Vicair SmartCells, these little pockets of air are captured in anti-friction material to prevent shear forces. The design is made up of an adjustable front and rear compartment, which helps prevent sliding forward and distributes pressure evenly. The perforated Twin O2 seat cushion allows you to fully machine wash the cushion without needing to remove the SmartCells as well as being more breathable.