The AP7-1-51-123 is a fully sealed, single-pole magnetic circuit protector with screw terminal and DC short time delay (51 delay code) designed for reliable circuit protection and power switching. This protector features an inrush pulse tolerance of 6 times rated current at 60Hz, with trip time characteristics ranging from 0.400 to 4 seconds at 125% rated current and 0.060 to 0.600 seconds at 200% rated current, measured at 45°C in vertical mount orientation. The unit has an approximate weight of 1.8 ounces (49 grams) per pole and includes an optional auxiliary switch rated at 3.0 amps at 120 VAC or 50 VDC. Unlike thermal protectors, the AP7-1-51-123 maintains consistent trip current across a wide temperature span and is available for DC circuit applications, making it ideal for aerospace, industrial control, and power distribution systems requiring accurate, inverse time-delay protection.