Our electronically controlled and adjustable system allows riders to open and close the exhaust valve with a push of a button. Choosing Dr. Jekill & Mr. Hyde means choosing for the best quality. Every Dr. Jekill & Mr. Hyde exhaust system has an integrated switch in a high quality clutch housing, with an optimal fit between all other components on the handlebars. Also the colour of the button integrates perfectly. This way it looks like it's part of the original setup. The button is fully weather-resistant and flickers a red light when activated for your convenience.