The FOX shock's custom valving, designed specifically for your motorcycle provides you with a safe and comfortable ride. Arnott's patents-pending kit offers TruAIR technology with a rugged air spring bladder and shock damper design. Not an air cylinder or air-assisted unit. For added ride comfort this kit includes FOX's adjustable rebound control dial. So you can quickly and easily adjust your shocks' internal damping characteristics. A feature not found elsewhere in the air suspension market.