MOFAST Bike Bells - Bring Us A Clear, Sweet, Loud Sound Specifications: Material: Aluminum dome + PP base Dome Diameter: 50mm (2”) Applicable: Fits handlebars with 21mm - 23mm (0.83Inch - 0.90Inch) outer diameters, recommend to use on the right side Weight: 40g Package include: 1 x MOFAST bike bell