The Guardian CR is designed specifically for use in Class 100 (ISO 5)and higher cleanrooms. It features an inherent balance circuitry, which maintains an ion balance of 0±5V. Ducts enclose the ionizers and each fan is tested for cleanliness to ensure that only clean air exits the unit. The Guardian CR has sophisticated internal monitoring circuitry which provides assurance that the unit is ionizing and that the balance circuit is functioning. An outlet allows power supply interconnection (daisy-chain) of units. Power requirement 120VAC,60Hz.