•Professional Utility Knife 4Pcs High carbon Steel Blades Set Anti-slip Retractable Auto-lock Paper Cutter Storage Design Knives Replaceable blades: includes 4 carbon-steel blades (1 loaded and 3 spare that store inside the body)Universal blade system: accommodates any compatible utility blade; easy push-button opening allows for quick blade changes (no screwdriver needed)Retractable: easily slide the blade out when working and retract it back inside the housing for safety when not in assort-grip ergonomic handle: helps ensure a secure, comfortable hold Durable construction and warranty: made of 72% aluminum, 10% TPR, 10% carbon steel, and 8% POM