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 Material: Aluminium Product Size: Approx: 9x7x7cm/3.54x2.75x2.75in Frequency Response Range: 100Hz-6KHz Battery Type: Lithium battery(Shipped with built in battery, without TF card) Battery Capacity: 120mah Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding. 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.