Features1LED lights, energy-saving, high-brightness, made of silica gel, are relatively soft and not easily damaged. 2It is easy to install and can be directly hung on the rail, line pipe, or other positions close to the pipe body under the seat cushion. 3It can be installed behind the car seat as a tail light, or installed at the front fork line of the handlebar as a front car warning light. The colorful design makes it safer to ride at night. 4Three flashing modes can be selected, including fast flashing, slow flashing and long time light. 5Because of its small size, you can easily carry it, with a special case that is waterproof.SpecificationItem Type: BicycleSeatTail LightMaterial: Silicone+PlasticSize: About. 6x3.5cm/2.4x1.4inBattery: 1 x CR2032 button battery 200mAh (included)Lighting Mode: Fast flashing, slow flashing, always on lightNote: When replacing the button battery, please do not be too violent.How to Use: 1. Unscrew the rubber cap;2. Take out the battery cover;3. Replace the battery;4. Put back the battery, put on the outer cap, and the test light is on or not.Package List1 x BicycleSeatTail Light