minum, Copper? Tube Materials: No theoretical limits.'KL' Finned Tube?? ?Manufactured exactly as the 'L' fin except that the base tube is knurled before application of the fin foot. After application the fin foot is knurled into the corresponding knurling on the base tube thereby enhancing the bond between the fin and tube resulting in improved heat transfer characteristics.?? Maximum Working Temperature: 260℃? Atmospheric Corrosion Resistance: Acceptable? Mechnical Resistance: Acceptab