Plantronics TR-11 Electronic Hook Switch Adapter (88608-11) Intended for Analog PhoneProduct Type Electronic hook switch AdapterMade Allows the user to answer and end a call remotely from the wireless headset without having to be at the desk to lift the handset receiver off the hook, or to press any buttons on a cordless phone handset. Connect any of the Plantronics wireless CS500-series headset (such as CS540, CS530, CS510, CS520) as well as the Savi W700-series (such as W740, W710, W720, W730) and Voyager Legend CS to a home cordless phone, an analog corded landline phone. Also works with Avaya or Lucent Partner phone.Note: Phone-line (RJ45) Wall splitter not included in the TR-11 package. Note: Older wireless headsets (such as CS55, CS70, CS70N, CS50, CS351N, CS361N and Voyager 510S) will NOT work with this TR-11 adapter (formerly TR-1). The interface on those charging bases is different than the one on the newer models listed above.