Features: Make from a Coppers alloy and Plastic materials, ensuring not easy to rusts or wear, even with frequent use. Ensuring safety with a clear and loud sound, our high decibels Bike Bells enhances alertness for effective and clear warnings while cycling outdoors. Builted with a waterproofs design for daily splashproof functionality, this bike Bells ensures clear audibility in wet weather. Feature a light weight and portable designs, this bike Bells ensures your handlebars shifting is unhindered. Easy to Install: Quickly install your bike Bells in just 2 step to enhances safety and easily activate the clear sound for a secure and attentively ride. Specifications: Materials: Coppers Alloy and Plastic Color: Black Color/Metal Color Length: about 5.0cm/1.97inch Installation port diameter: about 18-25mm/0.71-0.98inch Package Includes: 1pc Bicycles Bells note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.