aluminum fins Available molds as below: O.D.Copper TubesTube PatternMaterials of fins and tubingFin Pitch9.52mm(3/8”)25mm * 21.65mmAluminum or copper1.5, … , 4.5mm25.4 mm * 22mm1.5, … , 4.5mm7mm21mm * 12.7mm1.4, … , 3.6mm Customized service available upon request.