The 4008630 is a Guardian CR2000 ionizing overhead Air Blower a patented circuit that results in balanced delivery of positive and negative ions, which ensures that the unit will maintain an ion balance of 0 ±5V. Balance stability is further enhanced by use of SIMCO's unique ion shields at the fan outputs to reduce parasitic ion loss, ensures clean room compatibility using specially chosen components and materials, all fan and air bearing surfaces are manufactured free of silicones and equipped with SIMCO's patented built-in emitter point cleaners and a lockout switch to prevent tampering with the desired performance level. Built-in monitor and an outlet to daisy chain up to 10 units are also standard, sophisticated internal monitoring circuitry which provides assurance that the unit is ionizing and that the balance circuit is functioning. Aluminum enclosure with gloss white polyurethane finish.