"The TPI air curtain works wonders at keeping outside air out and inside air in. Features discharge vanes that extend the entire length of the curtain and adjust to optimize airflow performance. U.S.A. Thermal Overload Protection Yes, Speed RPM 562/1,636 Low/High , HP 1/2, Watts 199/509 Low/High , Volts 120V, Finish Type Powder-coat, Mount Height in. Up to 120, Mounting Type Above window or doorway, Assembly Required No, Material Type 20-ga. rigid steel, Amps 3.8/4.4 Low/High , Common Usage Maintains environmental separation w/a light flow of air, Variable Speed Yes, Air Delivery CFM 764/4,168 low/high. Cabinet constructed of 20 gauge rigid steel with baked-on epoxy powder-coat paint for durability Discharge vanes extends the entire width of the unit and are adjustable for optimum performance of air flow Blowers are forward curved centrifugal type, DWDI with corrosion-resistant scroll and wheel Motor is heavy duty, PSC, direct drive high efficiency and designed for use with SCR controller Permanently lubricated for long life and has thermal overload protection Has double insulation protection for quieter operation Quick disconnects supplied to accommodate easy installation and service of motor SCR Speed Controller supplied on all units compatible with the motor with low end adjustment for air volume control and savings in power consumption Electric heat option available"