The AirFX Magnum out performs all other air ride systems in both comfort and durability. Our purpose built shock technology incorporates a double sealed 63mm extra large composite piston. This requires less air pressure (40-70 psi) and creates a softer, smoother, and consistent ride. The specially designed shock body uses an upper spherical bearing and lower mounting stud to allow the shock body to pivot freely. This minimizes shock side loading and pivot friction while increasing response when cornering. Rebound is set by adding/removing air at the Schrader valve on each shock, allowing the rider to adjust the ride setting.