Knog Oi Classic Bell At last, an effective, sweet-toned bicycle bell that won't diminish, devalue or detract from the smooth lines and good looks of your finest bicycle. Minimal design - doesn't protrude, takes up less bar space. With a spring-loaded actuator built into the mount, the strike of the bell is firm and fast, enabling a good balance of volume and longevity of sound. Clean and simple single Allen bolt fitting (requires 2.5mm Allen key not supplied) The bell's internal moulded nylon mount is indented so you can clamp it over brake and gear cable outers without squeezing them. The bell is available in aluminium with a silver or black finish. It's also available in real brass or copper. Only 25g - we weighed a Knog Oi Classic Bell in large. For an insight into the intensive research and development that went into creating the Knog Oi Classic Bell, see wired.com review . 'Bike bells generally look & sound a bit ugly. But why? What if they looked sexy and sounded like an angel playing a glockenspiel? A bell with a beautiful tone, but also a remarkable style and choice of materials that embodies a rider's personality. The Small Oi fits 22.2mm bars e.g Mountain bike (near the grips), BMX & some old commuters. The Large Oi fits 23.8 to 31.8mm bars e.g. drop bar road bikes and some cruiser / commuters. Check where on your handlebar you are going to place the bell before you place your order.' Knog.