Specifications: Color: Silver, gold, Black dome diameter: 1. 2" Fixer outer diameter: 0. 83inch - 0. 90inch/21mm - 23mm material: high quality brass and ultra-tough plastic base Easy to install 1. Unscrew the fixed base. 2. The base is mounted on a bicycle handlebar in the proper position. 3. Tighten the screws to ensure the stability of the bicycle bell. Loud and crisp, secure escort for you and your family and friends. Suitable for any standard bike, scooter, motorcycle, Cruiser, tricycle, mountain road bike, electric bike and more. Package included: 2 x Bike bell