Adjustable 250mm (from center hole to center hole) shock absorber primarily used for (but not limited to) 50cc to 250cc ATVs, dirt bikes, go-karts, scooters as well as many other common models of powersport and mobility products. Spring coil diameter 10mm. Mounting hole inner diameter is 10mm, mount outer diameter is 27mm. Center post diameter is 9.7mm.