VECOO Mini Bicycle Bell and Horns for Adults Vintage Round Handlebar Mount with Copper Cover Safety Warning Bike Bells Materials: Pure copper cover + stainless steel hammer + resin base ADJUSTABLE SIZE :Fits for any standard straight bicycle or stunt scooter handle bar,bicycles handlebar tube outer diameter with 0.87inch - 1inch. MINI SIZE: The bike bell is 2" wide, including the black lever its 2.5" wide,it is lightweight 5.29oz. Easy to Install: This bicycle bells and horns is 360 degrees,Special screw design, Adjustable bell mounts for most handlebars,unscrew and screw it into place. Loud: Compact and loud,bring us a clear, sweet, loud sound,you flip back with your thumb and release,when people come from behind.