Surgelogic, Surge Protection Device, Brings Down Initial Surges To Manageable Levels & Can Offer Additional Value In A Cascaded SPD System, Compact Design Allows Surge Suppression To Be Installed Adjacent To Power Panels Or Directly On Sensitive Equipment, Designed & Listed For Indoor Or Outdoor Installation & Surge Suppression For Single Phase 3 Wire 120/240 Vac Or 2 Wire 120 Vac 60 Hz Electrical Services, 2 Devices Can Be Installed To Provide Suppression For 208Y/120 Vac 3 Phase 4 Wire Services, Field Proven Move Design Provides Response Time Less Than 50 Nanoseconds & Provides Lower Clamping Voltage Than Traditional Gas Tube Arresters, LED Indicated Operational Status & Convenient Back Nipple Mounting, NEMA Type 4X Rated.