Features: 16 Modes: Bike tail light has 6 light mode options, long bright, breathing flash, slow flash, fast flash, rhythm flash, ECO fast flash. You can switch the different modes according to your needs and different occasions. 2Multipurpose: Back brake light can be installed on all bikes, kids bikes, adult bikes, handlebars, dog collars or anywhere. Also can be used as helmet light, backpack light, warning light, etc. 3High Brightness: Bike tail light uses Fresnel principle design see through light cover with 16 LED beads. Create a high brightness and soft non blinding light effect. 4IPX4 Waterproof Rainproof, Easy Installation: LED bike tail light is made of IPX4 waterproof material, ensure the safe use in heavy rain, no fear of wind and rain with you forward. Easy to install. 5USB Charging Port, Indicator Light: Back brake light has a built in USB charging port (with USB cable). When the light is red, please charge. When fully charged, it will turn green. 6Lightweight Design, Metal Shell: LED warning bicycle back light mini lightweight, the shell is made of aluminum alloy, the surface is sleek and textured, craft exquisite. Item Type: Material: Aluminum Alloy, ABS Battery Type: Lithium Battery (Shipped with Built in Battery) Battery Capacity: 400mAh Battery Voltage: 3.7V Package Included: 1 x&nbspBike&nbspTail&nbspLight 2 x Bracket 8 x Tie 1 x Charging Cable 2 x Gasket 1 x Instruction Manual