Aspen 5 Ton Cased 3-Row A-Coil, 21 in, R-454B 20% Bleed TXV. Rifled aluminum tubing, enhanced aluminum fins. Embossed galvanized cabinets standard. Cabinet feature furnace connectors. Upflow, horizontal right, and horizontal left without field modification. Split access doors in front of cabinet for easy service access. Fully insulated foil-faced insulation. Aspen A2L Refigerant Detection System Kits are available for R454B refrigerants, and are certified to meet the requirements of UL 60335-2-40. Add the RDS Kit, part # ASP-A2L4SA, to provide a complete installation of the required sensor and mitigation device required by the UL standard.