ROCKBROS bicycle bell delivers powerful sound in a compact form. Produces a clear tone above 100 dB for safety and confidence on the road. Acoustic chamber generates rich sound with an effective range up to 65 feet, making it noticeable even in urban noise. Housing is made of stainless steel and polyamide resistant to moisture, rust, and mechanical impact. Ultra-thin aerodynamic profile fits tightly on handlebars 0.87 inches in diameter