Planet Bike Alias HID Lighting System High-quality bike light with 10-watt, high-intensity discharge (HID) bulb Solarc technology produces sunlight-caliber illumination using far less energy Integrated battery and light head eliminates wires for cleaner, quicker attachment 14.4-volt lithium-ion battery offers 2.5-hour (high) or 3.25-hour (low) runtime Fits 25.5 mm to 31.8 mm handlebars; weighs 0.84 pounds; limited lifetime warranty