Panasonic HYBRID IP-PBX KX-TDA50 - Manual (Page 80)

2.5 Information about the Other Cards
80 Installation Manual
2.5.4 SVM2 Card (KX-TDA5192)
Function
2-channel simplified voice message card for Simplified Voice Message feature.
Accessories and User-supplied Items
Accessories (included): Extension Bolt × 1, Screw × 1
User-supplied (not included): none