IULNK11-1-51-40.0-A is a single-pole hydraulic magnetic circuit protector from the IAL/IUL/IEL/LEL series designed for reliable circuit protection and power switching in international applications. This unit features a DC short delay (51) trip characteristic with a rated current of 40.0 amperes and operates with a DC resistance of 0.003 ohms at rated current. The device is configured with a single pole and includes a rocker handle with integral mounting, providing compact panel integration with a dimension "A" of 0.760 ± 0.007 inches (19.30 ± 0.18 mm) and panel thickness of 0.062 ± 0.005 inches (1.57 ± 0.13 mm). The protector is suitable for equipment requiring accurate circuit control and low-cost power switching, with applications in industrial and commercial power distribution systems where dependable overcurrent protection is essential.