This magnet is designed to help you measure your speed on a bike by connecting to a sensor.
This bike speedometer magnet is compatible with all cyclometers on the market. It can be attached quickly and securely to round or flat spokes, with no tools required.
Inside room: 100.0% Steel; Metallic structure: 50.0% Acrylonitrile Butadiene Styrene, 50.0% Nylon