Norton 5900 series aluminum low energy door operator. The 5900 series is a full-featured, extremely quiet, low energy door operator designed for moderate to high traffic doors. This cost-effective operator is for either pull-side mounting and is ideal for any application designed to meet the Americans with Disabilities Act (A.D.A). One touch programming combined with the operators built-in ability to calibrate door mass, offers Norton customers a smart, dependable solution. Functions: Power assist - when unit is activated, it allows the door to be opened manually with a force less than 5 pounds. Push and Go (selectable) - as the door is manually opened, the operator "senses" movement and opens door to the full-open position. Motor startup delay - delays operator opening. Infinite hold open - door will hold open at set position until power is turned off. Power latch (selectable) - increases latch power. Power input 120 VAC, 60 hertz.