Nitro 9000 series shock absorbers incorporate self adjusting "Velocity Sensitive Valving". This revolutionary technology varies the resistance valving incorporated in the shock according to piston rod speed. This allows for a super smooth highway ride and outstanding control in rugged off road situations from the same shock, without turning any knobs or shock removal for re-adjustment. Performance Proven 10-Stage Variable Valving • 200 psi Nitrogen Charged • Massive 1 3/8" Bore • Chromed Hardened 9/16" Piston Rod • Spring Loaded Piston Rod Seal • Military Spec. Fluid Rated To –50° C • Poly-urethane bushings for long life • Limited Lifetime Warranty • White powder coat finish • Smooth Highway Ride/Firm Off- Road