The beautifully resonant ring of solid brass. Available in solid brass and chrome-plated solid brass. The Duet is a traditional ding-dong bell. Color: Chrome Dome Diameter: 33mm (1.3 ) Fits handlebars with 21.7mm - 24mm (.86 - .95 ) outside diameters. What is it about the resonance of brass that is so universally pleasing? it s beautiful ring is clear melodius and long-lasting. It is primarily the alloys of brass (a combination of copper tin and zinc) that create a metal that readily vibrates to make the characteristic brass sound. The delightful fundamental tones and overtones of the vibrating bell are enhanced by the shape of the dome the thickness of the metal and the force by which the bell is struck.Let others on the pathway know you re there and enjoy the reverberating chime of brass with each strike.