The Oster #4F Detachable Pet Clipper Blade is produced from the finest high-carbon steel for professional and precise grooming. This detachable clipper blade is handcrafted to rigorous standards and then sharpened, finished, and tested using Oster's proprietary processes to ensure exceptional sharpness and durability.  Oster Clipper Blades are manufactured in the USA with superior craftsmanship and pride for reliable results groom after groom.