Maybe one of these similar products would be of interest:-

Stationary Bikes Exercise Bike Magnetic Speed Sensor Treadmill Speed Sensor

DYNWAVE Universal Treadmill Speed Sensor Sensor Replacement 2 Pin Speed Sensor Easy to Use Reed Switch Sensor Cable for Pedometer Running Machine, 80cm

Walking Treadmill with Full Length Handrails & Heart Rate Sensor, LCD Display Screen Elderly Treadmill, Recovery Fitness Exercise Machine Foldable for Home use with Holder, 300 lbs Capacity

Recovery Fitness Walking Treadmill with Full Length Handrails and Heart Rate Measurement, LCD Display Screen Elderly Treadmill

Electric Treadmill Portable Walking Pad For Elderly Treadmill Adjustable Speed