SMART AS HECK: Boost your riding safety with this ultimate smart bicycle rear light WATER-RESISTANT AND RECHARGEABLE VIA USB: All of Rayo’s features come sealed within an IPX4 waterproof body. A built-in USB port makes Rayo rechargeable at home, in the office, and from external power banks. ULTRA BRIGHT: Rayo offers innovative ultra bright LED lights BRAKE LIGHT: Upon braking, Rayo will detect that you are slowing down and will automatically trigger a brake light, warning traffic behind you. At the core of this feature is an algorithm that accurately tracks the movement of the bike, similar to what is integrated into modern drones. THEFT ALERT: Rayo sends your phone a theft alert via its mobile app when unfamiliar movement is detected on your bike via Bluetooth in short distances