In a nutshell, everything that currently works with our CS Series headsets with the exception of the Electronic Hook Switches for the older Series CS50 /55, CS70, CS351 /61 headsets. NOTE: The current EHS (Electronic Hook Switches) we carry for the standard CS Series are NOT COMPATIBLE WITH THE NEW Savi Series Headsets. Likewise, the Savi Series EHS’s are not compatible with the current CS Series Headsets we carry. Compatible Accessories for ALL Savi & CS500 Series Headsets: - HL10 - OLI (Online Indicator Light) - Productivity Pack (HL10 + OLI) - RD-1 POD - Plantronics TPA - WLS-Y ------------------------------------------------------------------------------------------------------------------------------ *check compat guide for phone models* Plantronics CS50 Electronic Hookswitch for Siemens Phones - Siemens/Funkwerk - p/n 37818-01- DISCONTINUED ------------------------------------------------------------------------------------------------------------------------------ Plantronics C…