SUNVP Rechargeable Bike Light Mountain Road Safety Bike Usb Rechargeable Bike Headlights Not a re-purposed flashlight! Light beam designed for biking, not just a round flashlight beam, this gives you a wide field of view and vertical cut off so you don't blind oncoming traffic. Your car's headlights are carefully designed for a wide beam, and so is the Illuminati. Charge the Li-Poly battery using all the USB chargers you already have for phones and devices, or just a computer. You'll be able to charge up nearly anywhere! It's bright! Lumen ratings are notoriously inflated and unreliable. For the record, this one is rated 300 Lumens and is brighter than many that falsely claim thousands of lumens. What you really need to know is that it's bright enough to not only make you visible to traffic, but to actually light your path so you can see that storm drain or broken glass before you're on top of it. CREE LEDs are the industry standard for quality and performance. 5-Second no-tool installation/removal. No screws to lose. No loose rubber bands or straps that can be dropped. No wires or external battery packs. Super easy to mount/remove on any handlebar 20-40mm diameter . Take it with you and don't worry about it being stolen. Easily switch from bike to bike. Weather proof, compact, side-visibility lights. Weight: net weight: 40 g, gross weight: 70 g; Dimension :Length: 65 mm, Width: 28mm, High: 23 mm ; Application : handlebar diameter: 20-40 mm