1.The product is based on Chinese Forestery Standards LY/T 1187-1996. 2.The professional chain for every kind of oil saw mainly is used for forest hag High Profile Cutters, Sharp Blade, longer Chain Life, Pre-added Lubrication before producing, running smoothly, less retractility. Grind chain after assembly, more wearable Made in super Nickel Alloy, The Best Cutting Capability, Better Impact Resistance. Slantwise Limit Tooth, Reducing Recoil. Maintain Conveniently, Working With Facility.