1. We use the Very high-purity copper which from yunnan. the purity is 99.95%. 2. We use the XPLE which come from Dow company Specifications:1) PE insulated/paired copper wire braided (paired copper tape, aluminum and plastictape) separately screened/PVC sheathed computer cable (flexible, double-steeltape armoured)2) PE insulated/paired copper wire braided (paired copper tape, aluminum and ...