C2G Legrand Telephone Splitter, Two Line Splitter with NEMA Type B Connector for Smartphone Devices, Male to Female Two Line Adapter, Ivory Phone Line Splitter, 1 Count, C2G 41062
Quickly plugs into a standard two-line telephone jack to connect a device to either line one or line two. A combined line one plus line two allows you to keep your two-line telephone connected.