The Knog Oi Classic Bell. Bike bells generally look & sound a bit ugly. But why? What if they looked sexy & sounded like an angel playing a glockenspiel? Knog Oi Classic Bell Features SIZE: Small bell fits bars 22.2mm diameter // Large bell fits bars 23.8mm - 31.8mm (How to measure your handlebars). WEIGHT: Small 18g // Large 28g MATERIALS: Aluminium with Nylon mount & acctuator BIKE ATTACHMENT: Nylon clamp with hex screw to secure bell to your bike. What about getting it on the bar? Just pop it over, give it a quick tighten up, and you're good to go. No sliding down the handlebars, no dismantling and re-assembling.