Trine 525 Clamp On Type/Tri-Volt Transformer With 120 Volts Primary AC, specially designed with a convenient screw bracket mounting clamp for standard 1/2" knockouts. This transformer has a sleek design with dimensions of: 2-1/4"D x2-3/16"H x 2-5/16"W. This transformer has electrical characteristics of: 8VAC--10VA--1.25 AMPS, 16VAC--10VA--0.62 AMPS, 24VAC--20VA-0.83AMPS. Caution to reduce the risk of electrical shock, disconnect power to the receptacle before installing or removing the power supply. When removing receptacle cover screw, the cover may fall across plug pins or receptacle may become displaced. And this power supply can be used only with duplex receptacle having center screw and secure this power supply in place by receptacle cover screw.