These heavy duty utility blades are made of .025 thick high carbon surgical grade steel and double honed to provide an ultra keen edge. Fits many utility knives and are for cutting drywall, fiberglass, wood, plastic, cardboard and more. 100 blades per box. The utility blade safety dispenser is plastic and dispenses any heavy duty utility blade. Used blade storage compartment. May be conveniently hung on wall or carried. It includes 100 blades.