Description: Long lasting endurance Easy to install and use Exquisite workmanship Lightweight and easy to carry Lights remind someone else of keeping distance, add safety This little tail light will ensure your safety while riding in the darkness. Usage:Attaches to All Cable Actuated Mechanical Brakes Burn Time :aprox,200h Steady or approx 100.000 Braking Processes Color:Clearly Visible Red Brake Led During Use Feature:Durable ,Water-resistant Installs with 2.5 mm Hex Wrench ,Found on All Standard Bike Tools Rounded Brass Screw to the Brake Cable Battery:Led Brake Light with Replaceable CR927 Button Cell Battery Shell material: ABS Weight: 20g Light Size: 3.8*3.8*1.8cm Specifications: Long lasting endurance Easy to install and use Exquisite workmanship Lightweight and easy to carry Lights remind someone else of keeping distance, add safety Usage:Attaches to All Cable Actuated Mechanical Brakes Feature:Durable ,Water-resistant Package Included: 1*Brake light 1*Tool