The TM506 Power Module Mainframe is just one of several mainframes available that are designed to hold and provide power for the TM500-Series of modular instruments. Up to six single width modules can be plugged in to the TM506, or a list of other slot combinations can be accommodated. The TM500-Series of plug-ins includes oscilloscopes, function generators, scope calibration equipment, DMM's, counters and power supplies. Also choose from pulse generators, operational amplifiers, bandpass filters, and current probe amplifiers. You may be able to fit every instrument you'll need into one small mainframe. Plug-ins sold separately.