Expandable Module for TOWERMAX-KSU 260v Protection * Protects 4 Incoming CO Lines using 110 punchdown block connectivity (3 wiring options)* Protects Pins 1-8 on 110 block Wiring: 110 End to (110,2 RJ14's or 4 RJ11 end) * Installs with just 3 screws to any TOWERMAX Module * Reusable cable ties * UL/CSA Replaces GUM4110