Skyjacker(R) Suspensions offers you a high quality shock absorber with true velocity sensitive valving. Shock absorbers, or spring dampers as it is called everywhere else except in the U.S., control the rate at which suspension springs compress and rebound. As the shock is pushed together, this is called bump or compression. As the shock expands, this is called rebound or extension. Absorbing the ‘shock' of bumps and suspension loading is actually performed by the springs in the suspension. The shock's real job is controlling the energy stored in the springs.Specifications: Collapsed Length 14.820 in. Extended Length 24.840 in. Shock Stroke 10.020 in. WARNING CA Proposition 65 Yes WARNING CA Proposition 65 Message California Residents- WARNING: Cancer and-or other Reproductive Harm. (For more information go to www.p65warnings.ca.gov) Description_DES NITRO SHOCK W/RED BOOT Description_EXT NITRO SHOCK W/RED BOOT Description_FAB Multi-Stage Velocity Sensitive Valving Description_FAB Twin Tube Construction Description_FAB 5/8 in. Diameter Hardened And Double Chrome Rod Description_FAB Red Polyurethane Bushings Description_FAB Includes Red Boot 15 Other Colors Available Description_FAB Limited Lifetime Warranty Description_INV NITRO SHOCK W/RED BOOT Description_MKT Skyjacker(R) Suspensions offers you a high quality shock absorber with true velocity sensitive valving. Shock absorbers, or spring dampers as it is called everywhere else except in the U.S., control the rate at which suspension springs compress and rebound. As the shock is pushed together, this is called bump or compression. As the shock expands, this is called rebound or extension. Absorbing the ‘shock' of bumps and suspension loading is actually performed by the springs in the suspension. The shock's real job is controlling the energy stored in the springs. Description_SHO Shock Absorber