This set allows ebike rider to safely cut off the power when Ebike brakes are applied. Although both twist and thumb throttles have spring mechanisms which will turn them back to their initial position, having switches on brake levers add a second layer of safety. While these Ebike brake levers are designed for V-Brakes and mechanical disc brakes, levers are long enough to be used on cantilever brake systems. One pair of electric bike brake levers included. Installed on 2.25cm diameter handlebar. High quality product. Made of aluminum. Light weight and durable. Special for electic bike and scooters. With electric motor shutdown (stop the motor when holding the lever). Quick release mechanism. Super easy to install. 1. This set allows ebike rider to safely cut off the power when Ebike brakes are applied. Although both twist and thumb throttles have spring mechanisms which will turn them back to their initial position, having switches on brake levers add a second layer of safety. While these Ebike brake levers are designed for V-Brakes and mechanical disc brakes, levers are long enough to be used on cantilever brake systems.