RPM Gage Power Instruments Inc Calibrator Control New Old Stock FS 1 MA DC 0-200

Description

Power Instruments Inc Calibrator Control RPM Gage New Old Stock FS 1 MA DC 0-200
Item is new old stock.
Not 100% certain but I think it goes with tachometer Control Type 921? Possibly others? Maybe you know more?
As far as condition it has been stored for quite some time. Minimal signs of natural aging but nothing major.
At time of listing I have multiples available so you may or may not get the one in the photos but all are of the same condition.
Questions are welcome.
Check out my other listings for more.