The next generation of Irwin? folding utility knives with patented BladeLock technology are engineered to keep the utility blade securely locked in the knife handle. The proprietary design addresses the most frequently cited user frustration, when blades accidentally pull out of the handle during use. Blade lock technology further improves safety by providing the user with the ability to change blades only when the release button is engaged and the blade holder is in the 45 deg open position. No other folding knife offers this level of blade security and user safety.