Analog Station Set and Central Office Line Protector Protects up to 16 wires 8 pairs using 110 punchdown in/out. Auto Resetting Technology PTC resistors open when a surge occurs, protecting your equipment, but unlike other fuses, the PTCs close again once the surge passes. Expandable modular system Applications Analog and Central Office lines for PBX or KSU Agency Approval UL 497A Secondary Grounding Requirements Uses Electrical AC Ground Recommended Grounding Impedance 0.5 Ohm Signal Perfect Circuitry Auto Resetting PTCs 160 mA 8 10 Ohms Clamping Level 260V Response Time 1 5 Nanoseconds Capacitance 50pF Suppression Modes Metallic and Longitudinal Wires Protected 16 wires 8 pairs Termination Type 110 punchdown