Buck-N-Boost transformer, 50/60Hz, 20 amp for a FBD® 562 or 772 frozen beverage dispenser. When to use a Buck-N-Boost transformer: 1) To raise or lower the line voltage to the range required by the unit, 2) to prolong the life of electrical components, 3) unit voltage reads below 200V when the compressor is ON, 4) unit voltage reads above 230V when the compressor is ON, 5) to maintain voltage in the 200-230 VAC range.