Panasonic KX-TDA0166 16-Channel Echo Canceller Card ECHO1616-Port Echo Cancellation Card (ECHO16)Provides echo cancellation for conference calls for up to 16 portsMounts on the KX-TDA0190 (OPB3) cardUse with KX-TDA100, KX-TDA200, KX-TDE100, KX-TDE200, KX-TDE600, KX-NCP500 and KX-NCP1000 systems..