1250-1S-120 is a single-pole general duty AC surge protective device (SPD) designed to protect high-risk electrical service entrance and branch panels in 120/240 V and 120/208 V AC networks. It features a maximum discharge current of 50 kA (8/20 µs), a nominal discharge current of 20 kA, and a maximum continuous operating voltage (MCOV) of 150 V with a UL voltage protection rating of 700 V. The device includes a UL 60691 compliant integrated thermal disconnect with visual fault indicator and remote signaling capability (250 Vac max., 2 A). With compact dimensions of 90 x 18 x 67 mm and DIN rail mounting, it operates across a wide temperature range of -50 °C to +85 °C. This SPD is ideal for installation at the front end of electrical systems, main switchboards, or near sensitive terminals in single and split phase applications.