Energy Efficient General Purpose Transformers are Designed for Linear Loads and are Most Frequently Used for Applications Such as Commercial Buildings to Supply a Variety of General Loads; Heavy Duty Ventilated Type 3R Optional Type 4, 4X (Stainless Steel) and 12; Front Accessible Separate High and Low Voltage Terminals; Connectors Suitable for Aluminum are Provided for Easy Cable Installation; Conduit Knock-Outs Standard on All Units (No Knock-Outs on Stainless Steel Enclosures)Specifications:Type Designation: NH3Construction: VentilatedPrimar