Serfas True 250 USB Reachargeable Headlight (Black, One) Produces a True 250 Lumens in overdrive mode with burn times up to 15 hours (50 lumen mode) USB Quick Charge in 3.5 hours Comes with USB Wall Adapter for charging Includes Handlebar and Helmet Mounting Systems Weighs just 150 grams with bracket and uses a replaceable Li-Ion Battery