Plantronics W478 Two Prong Adapter for M2250 Console- TC-W478BL 406978395
Plantronics W478 modular to plug prong adapter connects modular headsets to plug into standard PBX dual jacks (223A, 226A, etc)
4 conductor 616P modular jack in the back of the adapter is wired to PJ327 plugs mounted in shell on .625 inch (15.875mm) centers