Tube : Copper,Copro-Nickel,Stainless Steel Fins : Aluminium,Blue & Copper Tube Dia : 3/8",1/2",5/8",1" & 7mm Casings : Aluminium,Galvanised Steel,& Stainless Steel FPI : 6-16 Fins per Inch For use with all kind Refrigerants.All sizes shapes, capacities, circuits patterns, Fin/tube configurations.Duplicate of obsolete coils,custom design for new applications