SIMPLE-CAN is contactless adapter used to read vehicle CAN Bus data. SIMPLE-CAN adapter should be used in combination with:
It reads can bus data through the isolation of wires without damaging them and forwards signals to tracking device.
So in simply words : When connecting LV-CAN to the vehicle, you need to cut wires. SIMPLE-CAN allows to avoid that.
You connect SIMPLE-CAN to for example LV-CAN, and LV-CAN connects to device.
More information can be found at https://wiki.teltonika.lt/view/SIMPLE-CAN