Features: - Loud and effective electronic horn. - Great for town and city riding where audible presence is required. - Fits all handlebar types and sizes and is easy to fit. - With 6 different and loud sounds, increase the safety. - Sound button is very comfortable and sensitive. - Waterproof design, so also can be used on rainy day. - Easily install and fits all kinds of bicycle whose hand-bar diameter is 20-25mm. - Power is 9V battery included for long time use. Specifications: - Material: Plastic - Fits Tube Diameter: 20-25mm - Wire Length: 220mm - Package content: - 1 x Bicycle Alarm Notes: 1. Manual measuring, please allow 1 - 3mm error,thank you. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the picture. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.