There are basic survival knives, and there are survival knives for the professional. The 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 new Pro Series. The Pro Series are survival knives of near-unimaginable quality, durability and performance.