Trane 3.5 – 5 Ton 42000 – 60000 BTU 4MXC Four Way Cased Coil 4MXCC009AC6HCA has the all-aluminum Comfort™ coil from Trane. This particular four way unit is tried and to ensure the least number of leaks while ensuring quiet operation with the help of 100% foil-backed insulation.