The VE.Bus Smart dongle is two products in one:

First of all it is the Bluetooth accessory for our range of inverter/chargers: Multis, MultiPlusses, MultiPlus-II, MultiGrid, MultiGrid-II, Quattros, and our series of Phoenix Inverters with a VE.Bus port. When installed, use the VictronConnect App to monitor operation and also operate the system: change the input current limit as well as switch between Off, On and Charger-only modes.

Secondly it can work as a Voltage- and Temperature-sense device for the inverter/charger. This works with all models.