There are basic survival knives, and there are survival knives for the professional. Our original models of the F1, S1 and A1 have provided exceptional service for more than 20 years. And due to their outstanding quality and durability they will continue to perform for many more years. Nevertheless, our drive to continually improve our knives has led us to develop the Pro Series. The Pro Series are survival knives of near-unimaginable quality, durability and performance. We began developing the Pro Series knives back in 2010 and five years later, we are proud to offer three amazing Pro Series survival knives that are the world standard for survival knife performance and manufacturing. Simply put, a knife is a blade and a handle. To remain strong and stay sharp the knife must be made of high quality materials. But if the claim is made that a knife is "professional" then the knife and its builder has a responsibility to the user to raise the bar far above what is common. The Pro Series truly is professional.