VDO water temperature sensor14MM=1/4NPT17MM=3/8NPT21MM=1/2NPTworking principle:Working range: 0-120 degrees temperature: 97 ± 2 degreesworking way: NC (normally open)When the water temperature reaches the alarm temperature and the alarm switch is closed, the alarm mild will activate the water temperature decreases and the alarm change is turned off, the alarm gentle may be turned off the alarm temperature is reached, the reaction time is roughly 1 moment instructions:Width:connected to the meter of the positiveNarrow : linked to alarm mild of the advantageous