This is a Western
Electric 685-A subset, identical to several I pulled out of old
phone booths and old pay telephone locations around college
campuses. I did obtain permission to remove this one!
Again, this box is responsible for my interest in the pay
telephone. I found one covered in dust, spider webs, and decades'
old chewing gum. After cleaning it off, I became curious and
wanted to learn more about the pay phone that went with it originally.
These serve as a ringer for the phone. The
older pay telephone does not have room for bells. The 191G was
self-contained otherwise, but the later 233G needed the 685-A for its
induction coil and 425 network, labeled A in the photo. The
letter B denotes the contact screws where the phone line comes
in. The 685A subset was first used in 1958, I believe.
Previously pay telephones used several different types of subsets, like
the
534-A.
I have seen the 534-A subset used with a 191G in a 1950s photo
taken of Michigan State College students using a 191G pay
telephone. In addition to solid black, the 685 subset was molded
in gray and painted black at the factory, molded in black and painted
creme at the factory, and also molded in creme-colored plastic.