Bike bells generally look & sound a bit ugly. But why? What if they looked stylish & 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. Knog wanted to embrace a variety of riding genres, without compromising any. The Oi fits almost all cylindrical bars. The Small Oi is for 22.2mm diameter bars, while the Large Oi is for 31.8mm bars.