Buck 309 "Companion". It is my "ALWAYS" knife. For a few years it was the only one i carried. I can't bear to leave it home. It has been with me since 1977.It has been with me through the birth of my children, my grandchildren and the funerals of all my grandparents. I carry it because it takes almost no space. It cuts like a razor. May be one of the strongest pen knives. I EDC a Victorinox "Tinker" and a Spyderco Delica 3, i carry the "Companion" "ALWAYS". AREASON ? It is like a security blanket. regards Henry