Device Type: 16-Port Analog Single Line Telephone (SLT) Extension Card Model/Part Number: Panasonic KX-NS5174X (System Display Code: MCSLC16) Data Ports: 4x RJ45 Connectors (Provides 16 Analog Extension Ports) Compatibility: Panasonic KX-NS500, KX-NS700, KX-NS7300 IP-PBX Systems; Expansion Units KX-NS520 / KX-NS720 Key Features: Caller ID (FSK Standard) on All Ports, Message Waiting Indication, Supports Standard Analog Phones, Fax Machines & Modems Max Installation: 1 Card per Main Unit, 1 Card per Expansion Unit (for NS500) Slot Type: Takes 1 Large Extension Slot Key Specs: Panasonic KX-NS5174X, MCSLC16, 16-Port SLT Card, Analog Extension Card, Caller ID (FSK), Message Waiting, 4x RJ45, KX-NS500/NS700 Compatible Usage: Expanding Analog Extension Capacity in Panasonic IP-PBX Systems, Connecting Legacy Analog Phones, Fax Machines, and Modems to Modern Hybrid PBX Deployments