Here is the seller’s description, verbatim.
A beautiful example of RCA Victor’s 50-A inductor microphone. Yes, it has the full RCA Victor name on the plate, rather than just RCA, as found on most of these. This, I believe, indicates that this mic is older than those with just the RCA name. (Please correct me if I’m wrong.) Introduced around 1933, the 50-A was the first in their line of inductor (dynamic) mics, and became popular for a variety of professional applications. The name plate shows drawing #600854-G3 (rather than the later M.I. designation) and what I assume to be the serial number, B87301.
This microphone is in excellent condition. The finish looks nice and the plating is bright. There is a slight dent in the lower rear of the body, hidden when the cable connector is in place. Some of the black paint is worn off of the attached connector body. Altogether, these are very minor deficiencies in light of the overall good appearance of the mic.
The mic has been tested, and is in good operating condition. The diaphragm appears perfect. Included is a 12-foot cable fitted with the proper Cannon connector for the mic, with an old-style 3-pin Amphenol plug on the other end. The cable has the look and feel of old rubber, but is still in pretty decent shape. The mic’s mounting yoke is fitted with a threaded adapter to screw onto a present-day stand. (Stand not included.)