2 In 1 Bike Alarm Tail Light Multi function anti theft alarm tail light designed with bike alarm, COB leds and 200 degree wide angle design, the led bike light will make you more visible for other road users in dark night or daytime. Keeping you safe at all times.Smart Brake Sensing Technology Designed with the brake sensor, Automatic ultra bright brake light will automatically light up after braking.The bicycle light is super bright and highly visible from a distance, really catch attention to enhance your safety.Extremely Loud 115dB The bike security alarm can make a loud sound to draw people's attention. 115dB Loud can effectively scare thieves away, can also be used as bright taillight, intelligent remote alarm and electric bell. Two mounting methods for all types of bicycles (please refer to the instruction manual for details)IP65 Waterproof& USB Rechargeable IP65 grade waterproof bike tail light against splashing water from any angle. Built in 700mAh Polymer Lithium battery comes with a USB cord that charges from your computer, wall charger, power bank or any other device with a USB port. After charging for 3 hours, the tail light can work for 20 40 hours in 3 different modes. (Slow flash 40h, Breathing flash 30h, Steady on 20h)Easy Mount and Removable Saddle mounting bracket and adjustable silicone strap provided, make the bicycle rear light flexible to quick install or detatch on bicycles, seat post, seat tube bracket. Very convenient to unscrews from the mount cap for recharging.