The Axiom Zap 2 LED Tail Light helps keep you visible and alerts motorists and other cyclists behind you of your presence. Its red LED light provides 15 lumens of illumination and features three different modes to choose from (steady, pulse, and flash). The Zap 2 LED tail light is powered by a built-in lithium polymer battery that is USB rechargeable plus has an indicator light for battery and charging status. The quick-release rubber mounting strap fits seatposts or seat stays 19mm-48mm in diameter. Features: High-intensity red LED with an output of 15 lumens 3 light modes: Flash, Steady, and Pulse USB rechargeable lithium polymer battery Indicator for battery status and charging status Quick-release rubber mounting strap fits tubing 19mm-48mm in diameter Water resistant Charging cord included Specifications: Brightness: 15 Lumens Battery Type: Rechargeable (Micro USB) Run Time: - Beam Color: Red Color: Black Weight: -