TheTopeak Headlux 450 USB Front Lightprovides 450 lumens of light to keep you visible whilst on the move. The rubber strap provides bi-directional tool-free mounting and easy removal on aero and round handlebars or helmet. Topeak Headlux 450 USB Front Light Specifications Output: 450 lumens Lamp: 2 white high power LED's Battery: 3.7v 940mah lithium ion (integrated) Burn time: 1.5 hr (high), 2.8 hr (middle), 5 hr (low), 10 hr (blinking) Charge: Micro Usb Charge time: 2 hr approx Lamp housing: Aluminium / engineering grade polymer Strap mount fits aero / round handlebars & helmet IPX 6 waterproof Low battery indicator 6.7x4.7x2.7cm Weight: 73g