Tektronix 7B53AN Plug-In Module Dual Time Base for 7000 Series Oscilloscopes

Tektronix 5B12N dual time base for 5000-series scopes

Tektronix 5A18N Dual-Trace Amplifier Plug-In Module for 5000 Series Oscilloscope

Tektronix 7B85 Delaying Time Base 7000 Series Oscilloscope Plug-In Module (nice)

Tektronix 5A15N Amplifier Plug In for 5000 Series Oscilloscopes

Tektronix 7B87 Time Base 7854 7000 Series Oscilloscope Plug-In Module (nice)

TEKTRONIX TYPE 3B3 TIME BASE PLUG-IN MODULE As Is Untested