Low carbon steel tube1. single wall & double wall (dbundy tube)2. coating: copper, white zinc, yellow zinc, PVF3. dimenions:4.76 mm x 0.71 mm6.00 mm x 0.71 mm6.35 mm x 0.71 mm8.00 mm x 0.71 mm9.53 mm x 0.71 mm10.00 mm x 0.71 mm12.00 mm x 0.71 mm4.Usage: brake pipe, brake tube, A/C tube, compressor, evaporator5. Contact: Sarah Hu (skype: iamhuli)