KNOG Blinder Arc 640 USB Rechargeable Light LENS- Use of an optic design to provide a balanced ratio of beam width and distance to safely illuminate you and the path ahead. INTEGRATED USB PLUG- Designed to be exposed to the elements, 100% waterproof THERMAL MANAGEMENT- Automatically regulates the light output for optimum performance. BIKE ATTACHMENT- Tool-less removable silicone strap for bars 22-28mm and 29-35mm. MATERIALS- Polycarbonate housing and PMMA Lens. Hard-anodised aluminium fascia. UV-Resistant silicone.