This appears to be a "standard" type Diamond Disc reproducer (from the 1920s, judging by the "E" prefix). It would be suitable for any Disc Phonograph that came with gold plated hardware.
I'm curious about the cardboard spacer: those were a feature of the shipping boxes for reproducers, and it *might* indicate that this specimen had never been used - although the wear on the throat end seems to indicate otherwise.
Are you planning to use this in a Phonograph you have? You might first check the condition of the stylus with a high-powered magnifier: if there is any sign of chipping or wear, you will have to replace it to prevent record damage. Also, check to see if the gaskets need to be replaced (some of the later DD gaskets were made of cork rather than rubber, and have not hardened or deteriorated much over the years).
Thanks for your reply. The reproducer does look like it has some wear but it accompanying it is not only the cardboard spacer, but the wooden box which was designed to accommodate it. Thank you for the tips on using this piece.