Tektronix Type 1A2 Plug-in - Dual Trace for Oscilloscope 500 Series

Tektronix Type 3A3 Plug In, differential dual trace plug-in, untested

Tektronix Type M plug-in unit Tested Works

Tektronix Type 3B3 Plug-in - Time Base for Oscilloscope 564 w/ Manual

Tektronix Type D Plug In Unit High Gain Works

Tektronix 1A4 Plug-in - 4 Channel Amplifier for Oscilloscope 500 Series

Tektronix A53 Type D High-Gain DC | UNTESTED

Tektronix TM500 Series Aux Storage Plug-In