ITEM NAME:1 pc Brake Light LED Tail Light Safety Warning Light for Bicycle Bike Hot Descriptio n Description: Use: 1. The screw is loosened and the groove is aligned with the brake line of the rear brake. 2. Adjust the position and confirm that the brake wire is on the groove, then the screw lock 3. Pull down the brake handle to check if the brake light is on. If there is no reaction, adjust the position of the light. description: 1. A very practical bicycle brake light, one of the professional assembly of the rider. 2. When the bicycle brakes at night, the red light is on, warning the coming car to improve the safety of riding. Specifications: Name: Self-cycling brake light accessories road car disc brake tail light mountain bike v brake tail light riding equipment Size: 33*13*32mm Power supply: one CR1025 button battery Endurance: 50h Colour: Black Applicable: disc brake, car with brake line Material: ABS Package Included: Product list: 1pc Bicycle Brake Lights LED Taillights( without battery ) Note: Whatever the ending's perfect or not, you can't disappear from my world 1 pc Brake Light LED Tail Light Safety Warning Light for Bicycle Bike Hot.When the bicycle brakes at night, the red light is on, warning the coming car to improve the safety of riding. A very practical bicycle brake light, one of the professional assembly of the rider. 1pc Bicycle Brake Lights LED Taillights( without battery ).