Expandable Module for TOWERMAX-KSU 70v Protection * Protects Two-4 Wire Digital Leased Lines * Protects pins 1,2,4,5,7,8 on a RJ48S or RJ48C Jack * (2) RJ45 Cords 3 Screw Installation to any TOWERMAX Module * Can be used by Itself with Proper Ground * 1 set Per Jack * UL/CSA Replaces GUM0172