The sensor is to generate a pulse for the tripmaster where there is no workable electronic pulse from the car or where you want to take a pulse from another (non-driven) wheel. The pulse sensor can be installed to detect metal that passes by the head of the sensor.
The HR version can detect pulses up to 800 Hz which gives on average cars the possibility of about 15 pulses in a wheel circumference (in 1 rotation of your wheel).
Specification:
800 Hz
Thread of M12 x 35mm
2m Cable
PNP Transistor setup
12 Volt power supply (can be directly connected to the tripmaster)