The MK3-USB allows the following products to connect to a computer for configuration and firmware updates:
Multi
MultiGrid
MultiPlus
MultiPlus-II
Quattro
Inverter/Charger Settings in ECOmulti
EasySolar
EasyPlus
Inverters with a VE.Bus Communication Port.
More about Victron:
Victron Energy has a strong, unrivalled reputation for technical innovation, reliability, and build quality. Their products are widely considered to be a professional choice for independent electric power. Efficiently combining two or more distinct power sources is what they do best. Their products include sinewave inverters, sinewave inverters/chargers, battery chargers, DC/DC converters, transfer switches, battery monitors and more.