SY Bicycle Speedometer and Odometer Wireless Waterproof Cycle Bike Computer with LCD Display & Multi-Functions by YS https://a.co/d/4g1PqTS
You have to install a magnet next to a sensor in order for it to work. They have to be REALLY close together. I drilled a hole in the crab wheel and screwed the magnet onto it and attached the sensor to the back of the stand with zip ties. Can't wait to see how far they go!
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