Victron Energy VE.Bus Smart dongle is two products in one: bluetooth accessory and Voltage, Temperature-sense device The bluetooth accessory for our range of inverter/chargers: Multis, MultiPlusses, MultiPlus-II, MultiGrid, MultiGrid-II, Quattros, and 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 mod Can work as a Voltage- and Temperature-sense device for the inverter/charger. This works with all models For monitoring, the device is a great alternative in caravans, smaller yachts and motor homes for which the Color Control GX or Venus GX are a step too far.