In development for over 5 years, the new Renthal TwinRing sprocket will re-define the term durability in off-road drivetrain products. The longest lasting most durable off-road sprocket you can buy. The goal when developing this product was simple, create a high-quality rear sprocket that would outlast all others while keeping weight to a minimum. The TwinRing sprocket combines a specially enhanced 7075 T6 aluminum alloy center and high strength Electroless Nickel Coated EN8 Steel outer ring. The alloy center section keeps weight down and the steel outer ring provides durability where it is needed most.