Allows precise humidity control with a 20%-90% range. Change from humidification to dehumidification with a flip of a switch. Controls a humidifier, dehumidifier or fan. Durable powder-coated steel enclosure will stand up to the toughest conditions. Grounded piggy-back cord is easy to use. Ventilation louvers help avoid water accumulation. Built in 4% split differential. 15 Amps maximum/120 Volts/60 Hz.