The sewing machine knife blade is crafted from high-quality steel material, ensuring strength, durability, wear resistance, and scratch resistance. ROUNDED EDGES: Sewing machine upper and lower knife is made of exquisite workmanship, rounded and burr , to use without hurting your hands. STEEL MATERIAL: Sewing machine knife blade is made of premium steel material, which is strong and , wear and scratch PRACTICAL TOOL: Sewing machine blade helps to create many professional sewing processes and save a lot of time, thus greatly improving efficiency. EASY TO INSTALL: Serger machine upper and lower blade is easy to install and easy to use, very quick to complete the installation and save time.The replacement of both the Upper and Lower blade will ensure a smooth professional fabric cut APPLICABLE : Serger machine upper and lower knife for GN1?2 81?6 overlock machines, etc.International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.