Aspen 3.5-5 Ton Cased 3-Row A-Coil, 21 in, Flowrater Piston. Rifled aluminum tubing, enhanced aluminum fins. Air pressure tested at 500 psi, leak tested with helium, then sealed and nitrogen pressurized. Externally mounted flowrator body with Schrader valve for hiss-testing. Heavy duty plastic or metal drain pans. Embossed galvanized cabinets standard. Cabinet feature furnace connectors. Upflow without field modification; downflow application requires field kit (included). Split access doors in front of cabinet for east service access. Fully insulated foil-faced insulation. AHRI certifiable with all brand of AC and HP systems. ETL listed for use with both R-22 and R-410A when proper metering device is used.