USB Rechargeable Light: Built-in 330 mAh rechargeable lithium battery, can be charged via any USB port. Super Bright, Four Modes: Full Light, Half Light, Fast Flash, Slow Flash, there are four light modes, you can easily switch. Cycling Safety: The taillight emits an eye-catching wide-angle beam, which can be seen from several blocks away, you don't have to worry about being hit by others. Easy to Install: With the convenient one-touch removal button, you can easily slide the light in and out of the mount; the taillight's silicone mount is designed with four openings to fit snugly on most sizes of handlebars and seat posts. IPX4 Waterproof: Protects against splashing water from all angles. Whether it's heavy rain or fog, its water resistance, impact resistance and durability can withstand it; whether you're running, cycling or hiking, the safety light will guarantee your safety.