The MK3-USB allows the following products to connect to a computer for configuration and firmware updates:

Multi, MultiGrid, MultiPlus, MultiPlus-II, Quattro, VE.Bus BMS V2, Inverter/Charger settings in ECOmulti, EasySolar, EasyPlus, and Inverters with a VE.Bus communication port.

https://www.victronenergy.com/media/pg/VictronConnect_configuration_guide_for_VE.Bus_products/en/index-en.html