Irwin, Pro-Touch Retractable Utility Knife, Features A Smooth, 3 Position Slide, Easy Tool Free Entry With Push Button Operation Opens The Knife & Exposes Replacement Blades & Quick Change Mechanism For Blade Removal, Comes With 3" Blue Blades, Which Are Patented Bi-Metal Blades That Are Shatterproof & Stay Sharper 3 Times Longer Than Standard Utility Knife Blades.