This intelligent led taillights is suitable for night riding, with 4 light modes and intelligent brake sensing. The bright led bicycle rear light has a built-in 260mah rechargeable lithium battery, which is usb rechargeable. The charging time only takes 2 hours and can run continuously for 7-16 hours. The waterproof grade of the bicycle rear light is ipx6 soaking grade, which can safe to use even in heavy rain,in addition, it is made with abs waterproof shell, which is also more durable. Product details color black material abs pc type bicycle brake tail light power source usb charging battery powered mounting type rear seat mount orientation rear applicable type unisex-adult applicable bike models 24-29 inches applicable diameter seat post diameter below 33mm features lightweight and adjustable water resistance level ipx6 waterproof item weight 0.022Kg 0.05Lbs package weight 0.3Kg 0.7Lbs package dimensions 13.5Cm*7.9Cm*4.2Cm 5.3*3.1*1.7Inches quantity 1pc about this item 4 light modes there are 4 light modes for your choice:slow flash breathing flash fast flash steady on modes. The brightness of the bike brake light is 3 times higher than normal base on the high lumens cob led.Cob light beads makes you more visible,which is more bright at night. 3S smart brake sensing the bike light will highlight to remind the cars and pedestrians behind you when braking to make you safety ridding at night.When you start and stop while riding, the red light will illuminate for 3 seconds...