Black end caps. ECE approved. ESE (Electronic Sound Experience) enables the biker an unique driving experience with Full-Volume Sound. In addition to the OFF and ON mode, ESE is equipped with a third mode MEDIUM, in which the exhaust valve takes on an intermediate position and provides the rider with an additional, third, cleary distinguishable sound option. Power-Feature ESE provides you with power, if you require it! In the OFF and the MEDIUM mode, an additional burst of power is available. ESE automatically detects when a rider suddenly requires more power (for example while overtaking or in a dangerous situation that requires immediate power) and delivers the additional power without that the rider has to change the mode. Active Engine Protection: When you are in OFF mode and ESE detects that the vehicle engine is getting hotter and hotter, for example at a red light, the valve opens automatically a little bit in order to reduce the exhaust gas back pressure and to let the heat go out. If the driving profile changes to a thermally more uncritical situation, you will change to OFF mode again.