For auction is a vintage Micronta variable voltage control. I do not know how to test its function but can confirm that when plugged in it makes a faint hum and a lamp plugged into it dims when the dial is turned down. The dial is marked from 0 to 140 and states: input 115v @ 50/60Hz output 0-140v 5 amps. The outlet accepts two prongs, no third ground prong. The power cord is also of the two-prong variety. The shaft turns freely.