inner wire ISO-9001 material:steel ,plastic,pvc,galvanized,antifreeze,enviromental protection dia:1.25mm--3mm inner wire1x7,1x12, ... Port. through using of outer casing of round wire and SP straight wire,the products avoid being deformation and have high transmission ... cable can't be shedding and rusting ,and the inner wire become more flexible in the cable. Inner Wire AAA Class Quality