The RSH-1203P Type 1 Surge Protective Device (SPD) is a heavy-duty surge protector for three-phase 600V delta commercial HVAC applications. It protects systems from surges, enhances power quality, and filters EMI/RFI noise. Compact, rugged, and weatherproof (NEMA 4X), it clearly indicates operational status and uses GDT technology for maintenance-free operation. Uses long-lasting gas discharge tube (GDT) and thermally-fused metal oxide varistors (TFMOV) technology. Includes dual diagnostic LEDs and audible alarm. Type 1 SPD, NEMA 4X, and IP66 rated.