Designed to integrate seamlessly with compatible Giant and Liv helmets, the Numen Alumbra TL is the slimmest and most lightweight helmet-attachable tail light and features a unique quick magnet mount design for easy on and off as well as a built-in low-power indicator. Features: 20 Lumens maximum output ANSI certified lumens and runtime IPX4 waterproof Battery indicator alerts remaining run-time before powering off Runtime: 2.5 hours (High | 20 Lumens) 6 hours (Low | 10 Lumens) 7 hours (High Flash | 20 Lumens) 24 hours (Low Flash | 5 Lumens) Helmet Compatibility: Rev Comp Compel Roost Strive Lanza Coveta Rev Liv Comp Luta Series Specifications: Brightness: 20 Lumens Battery Type: Rechargeable (USB) Run Time: 2.5 - 24hrs (Mode Dependent) Beam Color: Red Color: Black Weight: 22g