Serious mountain bikers know that high-quality shocks are a must-have addition to any bike. The RockShox Monarch XX rear shock is easy to set up and makes bike riding a pleasure. These light weight shocks have a single Shrader valve used for filling both air spring chambers at the same time. Features include external rebound, hydraulic remote lockout, and a dual chamber air spring with self-regulating negative pressure. Enjoy safe and smooth mountain bike riding with this replacement shock.