All of our machined weights come heat treated and black oxide coated to prevent wear and corrosion. We offer 3 different profiles of weights. The first being our Hammerhead (heavy tip) weights which provide you with the most aggressive shift. They work great on big torque twin cylinder engines. Then we have our Tapered Tip weights, which are the same profile as the Hammerhead weights but they feature a medium tip for a slightly less aggressive up-shift and better back-shift. Last but not least we have our Taper Tip 2 weights, which have a similar profile as the Tapered Tip weights but they feature the lightest tip available for the least aggressive up-shift and the best back-shift.