Twin Shocks - 13" - Fully Adjustable - STX36 (HD357) Adjustable rebound and compression damping, Monotube shock with external hose reservoir, Length adjustable * 0.393", High pressure nitrogen gas charged, STX single tube design, 36 mm / 1.417" piston diameter, Adjustable preload with billet tool, Multiple spring rates available to accommodate a wide range of riders, Top level comfort, rideability, and performance, Hard anodized - precision CNC-Machined components, Low-friction shaft / seal head design, Fully serviceable and repairable