The Keysight 6051A electronic load mainframe accepts user-installable Keysight load modules for easy system configuration and future reconfiguration. The 6051A holds up to two 60501B, 60502B, 60503B modules, or one 60504B or 60507B module allowing up to 600 watts of total maximum power. One GPIB address is all you need for complete control and readback of all modules within a single mainframe.