Stanley 10-499 Quick Change 6-3/8" Retractable Utility Knife, specially designed to change blades fast without the need of a screwdriver. This blade cuts many types of materials like cardboard, drywall, plastic sheeting, and many other things. This knife features a three positioned retractable blade, it has a swing out blade storage magazine for easy access to the blades, an integrated string cutter for use even when the blade is retracted, and this knife accepts standard size utility blades.