Spa-Quip MK4 Temp SensorSpa Quip Davey new style in pool temp sensor with 3m lead(also available in 10m Q915445 10). Fits with a mini dim plug. Suits the following models: SP600 SP601 SP800 SP1200. This sensor is not required as these models have a in line temp sensor. They are just used if the customer would prefer to monitor the in pool temperature instead of the heater tube temp. Most commonly used on a swim spa for a more accurate temperature.