The Thermo Call unit has a built-in temperature sensor within the body and this will tell you by return message to either the App or via text message what the current temperature is, where the unit is mounted.
The external temperature sensor is required for measuring the temperature of a remote cabin, where the main unit is not fitted; either a separate cabin area to the main compartment, or a truck body for example.
This unit is also required if you want the temperature alarm function to operate via the app. This function allows you to set a high or low temperature setting and when that temperature is reached, the app will sound an alarm to let you know that action is required. This works particularly well for low temperatures when you want to protect the boat from freeze damage.
The sensor comes with approximately 1.3 metres of cable, and the wiring harness 'Y' adapter adds approximately 0.3 metres.
Extra loom extensions are available on request. The price varies on length required.