Looks like a late version in metal housing, they used to be in wood boxes earlier.
You can't use these in anything connected to the PSTN.
You have to construct a special high-voltage network. These were used for selective ringing of way stations. The ringing codes are mechanically programmed and pulses sent over the line used anywhere from 100 V to 400 V direct current, depending on the length of the line. Also, the impedance of the telephone sets attached was several thousand ohms, something like 7500 Ω, IIRC, to permit having many of them on the same line, many more than would be found on a PSTN party line, for example. The telephone set consisted typically of a 501A or 502A subset with a candlestick or transmitter arm.
Check out the RR catalogs and instructional documents in the TCI library. Those contain detailed info on these devices.