This adjustable link arm comes with a reversible insert. Testing determines the performance setting for competition use at a motocross track. With the insert in the forward position there is better weight distribution and chassis balance with a 6mm drop in ride height. By flipping the insert, you get a substantial lowering of the rear (22mm), for those using the motorcycle in less challenging conditions (or for less experienced riders). Recommended sag with the Rideng Link is 102mm. NOTE: With the insert in lowering mode, it is NOT recommended for aggressive track use, the shock will bottom out much easier due to the added leverage produced by this longer center to center distance.