For use with DC Ammeters For continuous operation, it is recommended that shunts not to be run at more than two-thirds 66%) the rated current under normal conditionsSpecifications: Continuous Duty 66% of Rated Current Full Scale 50 Milivolts Intermittent Duty 300% @ 3 Seconds 100% @ 5 Minutes Ratio 50A DC/50mV DC Shunt Type Resistive, Manganin Metal Element Weight 0.20lb (0.09 kg)