The Timber bells is designed to alert other nearby trail users of your presence. Using a on/off switch, the bell can be turned on, ringning activated by the bikes motion, or it can be silenced when not needed. The Timber bell offers a friendly way to warn other trail users of your approach. Features: Bicycle bell designed specifically for mountain biking for the purpose of alerting other trail users of your presence On/off switch for awareness when you need it and silence when you don't Bolt-on model fits 22.2-31.8mm handlebars with clamp and shim Slide the lever down for on, up for off or set it in between for a quieter sound Specifications: Model: Bolt-on Color: Black