Vivora Luno Rigid Air Seat - Standard FeltStandard (Approx. 65cm) Luno is a premium, anti burst, PVC inner ball within a tightly fitting, meticulously crafted cover. Functioning much like a bike tire does with an inner tube, the cover contains the pressure under load creating a solid sitting base that stays round with just enough give and bounce for a comfortable sitting experience. Luno comes complete with the cover, inner ball, hand pump, and accessories required to make the product work.