Upgrade Your Reflector to BKS-G4 Now! - BikeSpark’s Auto-Sensing Rear Lights detect bike deceleration with an innovative deceleration sensing algorithm, Vsenx (US Patent No.: 10427594 B2). Once deceleration is detected, BikeSpark increases the brightness to ultra bright for 2.5 seconds, alerting and improving the reaction time of the person in any vehicle traveling behind.

Automatic ON/OFF - Press and Hold the Control Button until the Light is On and you are good to go. Never have to remember to turn off your rear light again! BikeSpark turns off automatically after 1 minute of inactivity, and turns on when motion is detected. The perfect balance of convenience, battery life and riding safety.

Great Brightness meeting Regulatory Compliance - Super bright SMD LEDs provide excellent visibility, up to 50 lm with low power consumption. Besides, two constantly-on lighting modes meet ISO 6742 1/3/5, and Germany StVZO Regulations help you riding safely in the darkest nights.

Highly Reflective Reflector Meeting Regulatory Compliance : BikeSpark BKS-G4 equips with the world-class vehicle reflector. The highly reflective reflector not only meets German and EU compliance but also provides up to 30% more than required reflective brightness.

Made in Taiwan / Quick Mounting / 3 Lighting Modes / Daytime Brake Warning / IPX4 Water Resistance / Low Battery Indicator / Upgrade Your Reflector to BKS-G4 Now!