Oster? ProfessionalOster? Cryogen-X? Blades with Built-In Antimicrobial ProtectionSkip Tooth 1/8" cut/3.2mm.Blades Are Scratch and Rust-ResistantMade in USAThis is special blade with extra wide and long teeth for the progressive cutting in the wet, strong hair. It has specially hardened metal. It applied only at Easter metal hardening process ensures an extremely long life of the blades and constant good cutting performance. With this head blades stay sharp longer. It also increased blade durability.Cryogen-X AgION? Blades have advanced, silver-based AgION? antimicrobial protection built in to prevent the growth of bacteria, mold, and mildew on blade surfaces.The importance of regularly cleaning animal grooming equipment is often overlooked. Blades that are covered in hair and animal dander are ideal breeding grounds for microbes. Contamination of the blades can result in a more rapid disintegration of the metal, and regular cleanings are often time consuming and can be costly, and do not always adequately clean the irregular surfaces and crevices of the blades.The AgION compound provides protection against microbes by releasing silver ions to the surface at a slow and steady rate. This creates a self-cleaning surface that provides safe, continuous, long-term protection from bacteria, fungus and mold.