This is a small dual adjustable bench power supply, zero to 25 volts at .5 amp each with a fixed 5 volt 5 amp supply as well. An experimenters' supply I would guess. Need the manual. Some one had modified the unit to limit the voltages on each of the supply to values less than what the supply is capable of. Would like to restore proper operation. N2JH John R. Hagle Ripley, New York 14775