Features: 1.Anti Theft: The system has a flashing and alarm function that can warn motorcycle riders and prevent others from stealing. 2.Retrofit Speaker: The MP3 anti theft alarm can also be used as a retrofit speaker to provide excellent sound for a more wonderful ride. 3.Practical Design: The motorcycle anti theft alarm has powerful functions to connect Bluetooth and SD card to meet various riding needs. 4.Stable and Reliable: The frequency response range of the alarm audio is 100Hz?6KHz, the stable signal provides you with a reliable use experience. 5.Performance: The anti theft system is made of durable aluminum material, very lightweight and easy to install without much technical support. Specification: Item Type: Motorcycle Anti Theft Speaker System_x000D_ Material: Aluminium_x000D_ Product Size: Approx: 9x7x7cm/3.54x2.75x2.75in_x000D_ Frequency Response Range: 100Hz-6KHz_x000D_ Battery Type: Lithium battery(Shipped with built in battery, without TF card)_x000D_ Battery Capacity: 120mah Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding._x000D_ 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.