You are looking at one of the COOLEST add ons Lionel has produced.
This is an add-on meter to measure the voltage and amperage output on your older postwar ZW. THIS ONE is specifically for the OLDER pre-1969 ZW transformers. It can measure output on each of the four outputs from the transformer.
The Amp/Volt Meter for ZW controllers allows you to monitor the output of all four ZW channels with a digital LED display. Give each channel the exact power you want by watching the readings increase or decrease as you move your ZW handles. Simple to install, the Amp/Volt meter fits conveniently on the top of your ZW controller for easy monitoring.
CONDITION: C-7+ used but clean with everything you need. With original box and all the extras you see here. Some signs of use and handling on item. Some light shelfwear on box. Be sure to enlarge the pictures to see everything as up close as possible.