478
Original Western Electric HEADSET ADAPTER - The 478 headset adapter (often designated as W478, 478B, or GB478B) is a specialized telecommunications adapter. It bridges the gap between older vintage telephone systems and newer commercial equipment - The adapter converts a 4-conductor RJ9/RJ22 modular jack into a PJ327 dual twin-prong plug configuration.The Problem It Solves: Vintage Western Electric PBX switchboards, operator consoles, and early multi-line business phones use a traditional dual-jack interface (such as the 223A or 226A base). Modern office headsets use standard modular plastic clips (RJ9).The Interface: The rear of the adapter shell has a standard 4P4C modular socket. The front features two heavy-duty metal PJ327 prong plugs spaced exactly 0.625 inches (15.875mm) apart.Compatibility: It allows you to plug standard modular headsets (like those from Plantronics or GN Netcom/Jabra) directly into old Western Electric or Lucent operator slots - Because original Western Electric components are long out of production, third-party telecommunication companies manufacture exact replacements built to the original Bell System structural standards:Allen Tel Products: They manufacture the active replacement under part numbers GB478B-00 (Black) and GB478B-13 (Beige). You can purchase these through commercial electronics suppliers like CDW or directly via Allen Tel Products.Westek Electronics: They sell an exact equivalent under the part number TC-W478