Trailmaster Suspension 72450 Rear SSV Shock Absorber For On-The-Fly Adjustability Without Buttons Or Dials 2 3/8 Inch Diameter Cylinder Rear Shock Absorber With a Zero-Inch Lift, SSV Speed Smart Valving Includes Black Dust Boot And Urethane Bushings Low-pressure nitrogen gas charge to reduce the risk of oil foaming