The Sheffield 12854 Replacement Blade is a single edge razor blade designed for adult use. It comes in a pack of 30 blades, with a total of 3 packs included. Made of steel, these razor blades have a length of 0.5 inches and a width of 2.8 inches, making them ideal for respiratory protection applications. Each blade weighs 0.09 ounces, providing a reliable and durable option for maintaining personal hygiene and safety.