Radioshack Radio Shack Corporation Radio Shack Direct Connect Hands-free Headset Control Module #43-2013---connects Directly to Any Modular Wall Jack and Makes Any Modular Jack Headset-ready. Accepts Standard 2.5mm Headset Plug.---the Radio Shack Hands-free Headset Control Module Plugs Directly Into ANY Modular Rj-11 Telephone Jack so YOU Cananswer Calls Where It's Most Convenient for You! FOR Instance, If You're Going to Be in Your Workshop and You're Expecting an Important Phone Call, Just Plug the Headset Module Into the Eall Jack, and Add a Hands-free Headset-no Phone Is Necessary! With a Hands-free Handset and This Module, You Can Also Make Calls From Any Modular Corded Phone By Simply Adding a Duplex Adapter (430-2013)