STAR UNION Smart Brake-Sensing Bike Tail Light, USB-C Rechargeable Rear Light
Key Feature:
🚚 Ships from Our California Warehouse · 3–6 Day U.S. Delivery
🛡️ 1-Year Product Warranty · 30-Day Returns
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STAR UNION Smart Brake-Sensing Bike Tail Light, USB-C Rechargeable Rear Light





Smart Rear Visibility for Safer Everyday Riding
Improve rear visibility during commuting, road cycling and night riding with the STAR UNION Smart Bike Tail Light.
This USB-C rechargeable bicycle rear light combines smart brake sensing, automatic wake and sleep functions, six lighting modes, a built-in 500mAh battery and flexible mounting options for everyday cycling.
Why Riders Choose It
Smart Brake Sensing
The built-in motion sensor detects braking and deceleration. When slowing down, the tail light automatically increases its brightness to help alert vehicles and cyclists approaching from behind.
Auto Wake and Sleep Mode
In Normal and Breathing Flash modes, the light automatically enters sleep mode after approximately 40 seconds without movement.
When bicycle movement or vibration is detected, the light automatically wakes up and returns to the selected lighting mode.
Six Lighting Modes
Choose from six lighting modes to suit daytime visibility, night riding, urban commuting and different road conditions.
USB-C Rechargeable Battery
The built-in 500mAh rechargeable battery provides convenient everyday use without requiring disposable batteries.
The USB-C charging port allows the light to be charged using a wall adapter, power bank, laptop or other compatible USB power source.
Smart Power Level Indicator
The power indicator helps riders check the remaining battery level and recharge the light before the next ride.
IPX4 Water-Resistant Design
The IPX4 construction helps protect the tail light from light rain, splashes and road spray during normal riding conditions.
Do not submerge the light in water or expose it to heavy rain for extended periods.
Two Mounting Options
The included mounting accessories allow the light to be installed either beneath the bicycle saddle or on the seat post.
The quick-release design makes the light easy to remove for charging or storage.
Fit and Compatibility
Suitable for most road bikes, mountain bikes, hybrid bikes, commuter bikes and e-bikes.
This is an independently rechargeable USB-C bicycle tail light. It does not connect to an e-bike controller, display or wiring harness.
Specifications
• Product Type: Smart Bike Tail Light
• Smart Function: Brake Sensing
• Automatic Function: Auto Wake and Sleep
• Lighting Modes: 6 Modes
• Battery Capacity: 500mAh
• Battery Type: Built-In Rechargeable Battery
• Charging Port: USB-C
• Battery Indicator: Yes
• Water Resistance: IPX4
• Mounting Options: Saddle Mount and Seat-Post Mount
• Compatibility: Road Bikes, Mountain Bikes, Hybrid Bikes, Commuter Bikes and E-Bikes
Package Includes
• 1 × Smart Bike Tail Light
• 1 × Saddle Mounting Kit
• 1 × Seat-Post Mounting Kit
• 1 × USB-C Charging Cable
Please confirm the actual package contents before publishing.
Frequently Asked Questions
How does the brake-sensing function work?
The built-in sensor detects braking or deceleration and automatically increases the light brightness to help alert people approaching from behind.
Does the light turn on and off automatically?
In supported smart modes, the light enters sleep mode after approximately 40 seconds without movement and wakes when bicycle movement or vibration is detected.
How many lighting modes does it have?
The tail light provides six lighting modes for different riding and visibility conditions.
Where can the tail light be installed?
The included mounting accessories support installation beneath the saddle or on the bicycle seat post.
Does it connect to an e-bike wiring system?
No. The light uses a built-in rechargeable battery and charges through USB-C. No e-bike connector or controller wiring is required.
Is the tail light waterproof?
The light has an IPX4 water-resistant design suitable for light rain and road spray. It should not be submerged in water.
Most U.S. orders ship from our U.S. warehouse and are usually delivered within 3–6 days.
Orders to other countries, out-of-stock items, and customized products may ship from China and are usually delivered within approximately 14 days.
We want you to be completely satisfied with your purchase. If you have any questions, concerns, or complaints, please contact our online support team or email us at grt@star-union.net. We will respond within 8 hours.
Items can be returned or exchanged within 30 days of delivery. Please contact us before returning an item so we can help you with the next steps.
