The DEWALT TOUGHSERIES Retractable Utility Knife has a slider mechanism that delivers 2X longer life and debris resistance. Engineered to provide durability in harsh conditions, this TOUGHSERIES knife helps limit blade tear out via a secure blade lock, that retains the blade whilst cutting.It has a durable zinc construction, ideal for harsh jobsites. The ergonomic work handle fits comfortably in your hand. The slide-and-click blade changing system is quick and easy to use, insert blades with the press-free blade changing system. There is also convenient onboard storage for up to 10 blades.Supplied with 1 blade.