The MotoSport.com Renthal Twin Ring Sprocket Kit includes ONE Steel Countershaft (Front) Sprocket, ONE TwinRing® Rear Sprocket, and your choice of ONE Premium 520 Drive Chain, each with the following features: Sprockets / Chainwheels Included: Renthal Front Sprocket: When looking to replace your sprockets, Renthal sprockets are an easy choice because of their strength and inexpensive price tag. Also known as "chainwheels", Renthal front sprockets are precision manufactured to withstand the rigors of Supercross, motocross, and enduro racing. Renthal Front Sprockets are made out of 655M13 nickel-chrome-molybdenum alloy steel. What does that mean to you? Ultimate strength and hardness. Self-cleaning mud grooves prevent the build-up of dirt.