RK's MS series chains are low-cost non-sealed motorcycle chains featuring 4 side (Quad) rivet staked pins. When pins are quad riveted they are stronger and more stabilized; which results in increased stress resistance due to high engine loads and makes the transmission of horsepower to the ground more efficiently. As a result of the change to the 4 rivet staked pins the addition of solid bushings and the application of RK's new specially formulated coating; RK non-sealed chains now show a 40% increase in chain life! RK non-sealed chains perfect for low displacement motorcycles that did not come from the factory with sealed chains. Weight: 0.78 KG Max CC Rating: 125cc Street Master Link Type: CLIP Chain Length: 136 Fits: Aprilia RS50 2006-2010