Panasonic HYBRID IP-PBX KX-TDA50 - Manual (Page 78)

2.5 Information about the Other Cards
78 Installation Manual
2.5.2 ECHO8 Card (KX-TDA5166)
Function
8-channel card for echo cancellation during conferences.
Accessories and User-supplied Items
Accessories (included): Extension Bolt × 1, Screw × 1
User-supplied (not included): none
Note
To establish a conference call involving 6 to 8 parties, install an ECHO8 card and enable echo
cancellation for conferences using the KX-TDA50 Maintenance Console. For details, refer to "Echo
Cancel—Conference" in "2.8.17 [2-9] System Options" of the PC Programming Manual.