... and easy install Name: 35mm bicycle bell,flick bellmaterial: aluminium alloy+plasticcolor: red,aluminium plain,golden,black,etc.how to use:press switch ... ,etc.It is very easy to install,children,woman they all can do it,only need a screwdriver.diameter: Φ35mmweight: 20 ... according to QB/T 1723-1993<>,below is certificate: sell aluminium alloy color bicycle bell mountain bike cell,mini flick bell