ROCKBROS Bike Tail Light Rear Light USB Rechargeable Bicycle Taillight Waterproof Bike Back Ultra Bright Smart Cycling LED for Safety, Warning, Mountain Road Bikes with 5 Modes, up to 100 Hours

• 5 LIGHTING MODES: Constant brightness - 10h, breathing flash (7 colors) - 12h, alternating red and blue flashing - 30h, red flashing - 30h, bilateral red flashing - 100h. Battery life ranges from 10 to 100 hours, depending on the mode selected.
• SAME FREQUENCY MODE: Double-click the button to switch to this mode. when teammates equipped with the same bike taillight and ride near each other, The taillights will automatically change to maintain the same flashing pattern and frequency.
• FAST USB CHARGING: This bicycle rear light has a built-in 300 mAh polymer battery, which has a fast charging speed. And there are 4 battery indicator lights on the smart bike light, when there is only 1 indicator light left, the remaining power is less than 25% and needs to be charged.
• THREE ADJUSTABLE BRIGHTNESS: When the bicycle rear light turns off, long press can adjust the brightness in three levels (low, medium, high), allowing you to choose according to the environment. And the rear light has medium brightness by default.
• MORE DETAILS: IPX6 level waterproof and dustproof, splashing water from all directions will not affect the bike tail light. There are 2 installation methods: seat post or saddle arch installation.

ROCKBROS Rear Bike Light Ultra Bright LED Bike Back Light USB Rechargeable Bicycle Taillight with 4 Lighting Modes Waterproof Cycling Light Tail light for Safety Warning Mountain Road Bikes, up to 95 Hours Brand: ROCKBROS Color: Black Charging: USB Battery: 3.7V, 300mA Weight: approx. 55g Lamp Size: approx. 40*34*34mm Material: Aluminum alloy Suitable for bicycle saddle arch with spacing of 47-54mm. ROCKBROS promises to offer 100% satisfaction to every buyer. If you encounter any problems or have any questions for us, please do not hesitate to write to us through Amazon. We will offer you the best possible solution.