Wrench: one end with the same single-head wrench, wrench the same with the other end, both ends of the screw turn the same size bolt or nut. The use of 45 carbon steel or 40Cr alloy in the whole forging, heat treatment, quench hardening, thin body pull, torque super strong stain resistance within the rounded design, to increase contact surface, the depth does not hurt the nut bevel design, easy to narrow space Operating Specifications: opening the same size and plum, 17mm - 90mm Our products Hardware product supervision and inspection by the State Department from time to time continuous random sampling, according to national standard GB-10686-10691-89 standards for quality supervision and inspection, and doing destructive testing various technical indicators have reached the level of quality products, and certification by international standards; 2004 was awarded the North China Alloy Casting Product Development Award Committee; the same year by China Light Product Quality Assurance Center issued a "national quality and prestige double safeguard demonstration unit "bronze medal and certificate.