Irwin 10504236 ProTouch Retractable Blade Utility Knife The Irwin 10504236 ProTouch Utility Knife has been developed on the basis of research based on the needs of professional users. This innovative range of knives meets the highest standards of today\'s professionals, to whom safety, durability, convenience and comfort are of the utmost importance. A retractable knife which is ideal for general maintenance jobs. The Bi-Metal Blade combines spring backing steel with an electron beam welded high-speed steel edge. Spring backing steel offers flexibility reducing the chance of shattering for operator safety. Heat-treated HSS cutting edge offers long blade life and edge sharpness. Lasts up to three times longer than carbon steel blade. The knife comes with 1 blade. Features: Pro-Touch ergonomic grip Magnet holds the working blade in place  Ideal cutting angle for reduced fatigue  Tool-free easy access to spare blades (not included) Spring-loaded push button opener   Comes with a bi-metal blue blade  Inside storage clip holds five blades securely