Renthal Twinring sprockets are truly unique hybrid sprockets that will keep you spinning around the track. Twinring off-road sprockets are made of long-lasting and durable material a high-strength, ultra-light 7075 T-6 aluminum inner core and an electroless nickel coated steel outer ring are permanently bonded together. They are precision CNC-machined to tight tolerances and feature a flat face design that keeps weight to a minimum and makes them as narrow as regular sprockets! Self-cleaning mud grooves are added between every tooth on both sides to prevent dirt buildup, plus flat socket head screws add additional strength to the sprockets. Try double durability with less weight on your dirt bike with the addition of Twinring sprockets from Renthal.