A.Y. McDonald 747H20 Guardian Emergency Water Powered Back Up Sump PumpA. Y. McDonald Guardian 747H20 Emergency Backup Sump Pump will protect your property during power outages or sump pump failure. Designed for ground water, sump crocks in homes, motels, and hotels, schools, hospitals, industrial buildings, computer and record storage rooms. A. Y. McDonald Guardian Emergency Water Powered Back Up Sump Pump Features Made in the USA Patented Activation Valve for Positive ON, Positive OFF Designed for Intermittent or