Initially developed for our ATV shock conversion kits made in 2004, we set out to develop the best adjustable shock under $250. Due to popular demand, we have created the DIAMOND+ model shock with added compression adjustment and a high quality machined body for only $399! After years of feedback and improvements, we are happy to provide a shock that can be used on ATVs, Motorcycles, and other off-road vehicles to upgrade stock suspension performance. Compatible with our Adult ATV Shock Conversion Kits. (Same size as 400ex stock shocks) These shocks are adjustable in preload, compression, and rebound: Preload can be adjusted using included tool to tighten the nut/collar above spring coils. Compression can be adjusted by twisting the top knob on the reservoir. Rebound can be adjusted by twisting the bottom knob on the reservoir.