DeArmond (Rowe) RHC-B Acoustic Soundhole Pickup (c. 1960/1961)
This is a good, used DeArmond round soundhole pickup. Output meters as it should. Output is through a 1/4" T/S male jack.
There are variations on this pickup, but from what I can determine, it was made around 1960/1961.
It has five exposed pole pieces (not six), non-adjustable pole pieces, a roller volume control, and the DeArmond name is in the chrome mounting plate, not on the pickup cover.
The cover is stamped "DeArmond, H.N. Rowe Co., Toledo, OH USA".