The video shows the meter in normal operation.
The calibration function doesn't work properly. The CAL control affects sensitivity for normal operation, but isn't able to get the meter needle into the CAL region in the CAL mode.
Includes Gen Rad 1560-P5 microphone and leather case.
The 1551-C requires two D cells and a 67-1/2 volt No. 467 NEDA 200 battery or a Model 1262B Power Supply. None of these are included in this listing.