The E-Bike Rack Pro StVZO E40 rear light is StVZO-certified and features 360° visibility Vivid Optics which floods bikes’ surrounding area with light for improved rider visibility. Twelve high-output LEDs provide 40 lumens. Rigorously tested to IPX7 Waterproofing standards, it is built to withstand various weather conditions.It includes 50 and 80mm rack mount spacing, Stainless Allen key hardware and an integrated 135 cm power cable connecting to the e-bike’s motor/battery system. E-Bike compatibility: 10.5 13.5V input, 1.7W.The e-bike lights are powered by the motor/battery of an e-bike and need to be manually installed. Proper installation may require some disassembly of the bike and motor (depending on make and model, battery type) and additional wiring to connect the light to the motor. Please contact the e-bike or motor manufacturer for installation instructions. It is highly recommended to have a trained e-bike professional install your lights for you.