USE: It employs the dual-magnetic loop - Hall elastic angle difference to detect the dynamic torque, which is converted to DC signal and sent to the controller. COMPATIBILITY: Electric bicycle speed sensor (known as PAS, wheel mounted sensor), it has superiority to match well with all electric bicycles available in the market. PRACTICAL: 1:1 power assist. Make cycling easier and funnier. ERGONOMICAL DESIGN: It is a high-tech component designed for electric bicycle with ergonomics. GUARANTEE: If you are not satisfied with our product received, you can apply for unconditional return and refund within 180 days. In terms of any problem of this product, you can send emails to us at any time. We will reply you as soon.