Our throttle block is stronger and lighter than the stock plastic throttle blocks and has been redesigned and reengineered into a new two piece design. The two piece design allows you to install this without destroying your handlebar warmer. A special groove is machined into this block to allow handlebar warmer or thumb warmer wires to be routed through without pinching. This throttle block is CNC machined from 6061-T6 alloy aluminum and offers 3 different pin pivot positions which allow this part to open 36mm to 48 mm bore carburetors or throttle bodies. INCLUDES THUMB LEVER.