For exposure consistency in the color as well as black & white darkroom it is necessary to compensate for line voltage fluctuations. Only a capable voltage stabilizer can do that.
This is a SOLA constant voltage transformer or stabilizer. As the name indicates, this is not a solid state but a transformer based voltage stabilizer. This is a heavy duty, industrial strength unit rated at 190/380 primary and 260/520 secondary for a frequency of 60 herz and a general line voltage of 118 volts. This makes the unit imminently useable in a 110 volt powered darkroom or photo lab with virtually any enlarging equipment. The unit has proven to be extremely accurate and reliable. It is in good condition, ready to use.