IUGH66-1-51-5.00-01 is a hydraulic magnetic circuit protector from the Airpax IUG series, designed for low-cost power switching, reliable circuit protection, and accurate circuit control. This single-pole device features a 5.00 amp current rating with delay curve 51 (DC application), providing no trip at 100% rated current and trip times of 0.500 to 6.5 seconds at 125% overload. The unit includes a black toggle handle marked with ON-OFF I-O indicators. Available in series, shunt, relay, or dual coil configurations, these circuit protectors are suitable for automation systems and equipment requiring compliance with international standards.