LUCKYSUN 1100 Lumen CREE XM-L T6 USB Bike Bicycle Light Headlight LED Headlamps Flashlight Compatible 3.7V to 12V Waterproof(Pack of 2pcs) Wide Voltage Input: 3.7 to 12V Using XM-L T6 LED,intelligent control circuits. Can be used as Headlamp or Bicycie Light.( 4cm head diameters and 5cm length) USB connector,The length of the USB line is about 1.2 meters. 3 switch Mode: High//Low/Strobe