Ultra-bright taillights 2 units - 100 lumens COB Leds of 240 visibility, transparent shell, compact size of 35g, 7cm, Ipx 4 waterproof for any road bike, MTB, hybrid or commuter bike. 6 Modes: Full brightness solid red-4h, brightness solid red 50%-6h, flash red-8h, strobe red-8h, blue-solid-4h and flash red/blue-10h. Blue light is use for emergency 2 hours charging = 4-8 hours working with built-in 600mAh lithium battery. For fast charging, simply connect the bike light to any USB device such as a power bank, car charger or an AC plug adapter. QUICK AND EASY TO INSTALL: With a quick release button, you can easily mount it on any bike, road bike, mountain bike, hybrid. No tools required. It is widely used on bicycles, undercarriages, clamps bags, motorcycles, helmets, baskets, wheelchairs, scooters, strollers, harnesses, reflective vests, backpacks, etc. 1 x User Manual.