These variable transformers are encased to protect the inner circuitry from spills and splashes; a must for messy, accident-prone laboratory environments. These units provide stepless, adjustable AC output to a wide variety of laboratory equipment. Voltage is varied by a simple twist of the knob on the face of the unit.

These instruments have a triple wire, 6 ft cord with a tri–plug, graduated knob, fuse, safety switch and grounded outlet. Unit 7520D includes an integral ammeter and a voltmeter. Input voltage on all units is 120 V.