This pack of 10 General heavy duty Hook Blades is specifically designed for use with General Utility knives 850 and 855. The blades are made of durable stainless steel, ensuring long-lasting sharpness and precision. These utility blades are ideal for cutting through tough materials such as roofing, carpet, and drywall.Manufactured in the United States, these blades are of high quality and can be relied upon for heavy duty tasks. The blade's hook shape allows for easy cutting of thicker materials, making them an essential addition to any tool kit. With the convenience of 10 blades in one pack, you'll have plenty of replacements on hand for when your blades inevitably dull.