This is an effective remote control and alarm sensor that helps to protect your bike well without worrying about losing it. It is super loud, easy to operate and easy to install, and it can perfectly protect your shop, office, home, car, house or any place that needs protection. Made of high-quality plastic material, it is durable and safe to use. A suitable handlebar diameter is 3cm. The length of the alarm is 9.8 cm, the width is 3.7 cm, and the height is 6 cm Suitable for bicycle, home, office, shop, etc. Item Name: Bike Alarm Lock Material: Plastic Batteries: 1 x 9V Battery (Not Included) How to Use: Press the red button to arm the defense, and it will beep once; press the gray button to cancel the anti-theft, and it will beep twice. Size Details: Suitable Handlebar Diameter: 3cm/1.18" (Approx.) Lock Size: 9.8cm x 3.7cm x 6cm/3.86" x 1.46" x 2.36" (Approx.) Notes: Due to the light and screen setting difference, the color of item may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Anti-Lost Buckles 2 x Nuts 4 x Screws 1 x Remote Control 1 x Bike Alarm Lock