1.Made by high purity copper, provided reasonable price 2.Certificate:ISO9001, RoHS, CE 3.OEM ... .5mm, E6.8mm, D5.6mm, d3.4mmSNB5.5-4S for #8 screw, 12-10 gauges, B8.3mm, L19.5mm, F7.5mm ... , E6.8mm, D5.6mm, d3.4mm SNB5.5-4L for #8 screw, 12-10 gauges, B9.0mm, L19.5mm, F7.5mm ... , L25.5mm, F12mm, E6.8mm, D5.6mm, d3.4mmSNB5.5-8 for 5/16 screw, 12-10 gauges, B14.0mm, L24 ...