Ideal for balance, strength and rehab exercises, the Origin Air Balance Disc targets ankle, foot and knee stability. The user can increase or decrease the amount of air inside the disc to vary the stability of the cushion, and therefore the difficulty (less air makes the surface more unstable). Diamater 340mm, thickness 40mm. SPECIFICATION: Brand Origin Usage Home Use, Commercial Use Condition Brand New Warranty All Origin products are covered by a 12 month warranty from day of purchase. The warranty only covers manufacturing faults and defects. Wear and tear is not covered.