Description: This waterproof USB bike rear light features a builtin lithium battery and supports USB charging. And it will stop charging when the battery is full. The bike USB taillight has a small size and is lightweight, portable, and won't affect your cycling. The bike rear warning lamp comes with an antiskip silicone snap, so you can use it to easily mount the lamp on the bike. The bike LED light is bright and low power consumption and can alert people to remind a distance, which makes your night cycling safer. The bike taillight is durable and waterproof and has multiple light modes to meet your different needs. Specification: Material: Plastic + Silicone. Light Source: COB + LED. Light color: White Light, Red Light, Red White Light, Red Blue Light. Lighting Mode: Normal/Slow/Sequential/Fast. Battery: Built in 500mAH Rechargeable Battery. Power supply: USB charging. Charging Time: 2 hours, working time about 5 hours.(different lighting modes have different power consumption) Waterproof: Yes. Brightness: 100lm. Application: Bicycle, Scooter, Electric Car. Size: 80x15x20mm. Notes: There might be a bit color distortions due to different computer resolutions. There might be a slight errors due to different hand measurement. Package Includes: 1 x Bike taillight.(Battery builtin) 1 x USB cable. 1 x Silicone snap.