The Acewell S4 speedo cable (hall sensor cable) replaces the original speedometer drive cable on your bike, providing a simple and accurate installation for your Acewell computer. The ACE-S4 fits the Honda CRF450, as well as many Yamahas, including the WR series, KTM, Ducati, Husky, CCM, Husaberg, Moto-Guzzi, and MZ model motorbikes.