Gas pressurization of shock. Added protection for the shock rod and oil seal. SHOCK SPECIFICATIONS Increased fluid capacity to operate cooler. Rebound Bumper. Provides smoother piston travel & greater responsiveness.
Seems they don’t make rhem at all like they used to, in just two months these on the rear of my 06’ sprinter are already about shot :( Save your money and don’t bother buying!!! My pair from 20 yrs ago lasted 15yrs on my 3/4t F150