This is an excellent quality folding knife made in Seki, Japan by Seizo Imai circa 1980s for Explorer. It is marked Stainless Steel Japan on the black blade and KGB 400 on firm rubber handle. The hole in the handle does not allow one hand opening as the backspring is fairly stiff, so it is for opening with two hands. Comes with black leather sheath. Seizo Imai was one Seki, Japan's finest craftsmen and most famous knifemakers of the modern era. His collaboration with Parker spanned nearly two decades. He made knives for Parker, Frost, Browning, Explorer, Compass, Condor, and many others, including his own brands Imax and Seizo Imai. His custom Loveless style knives are works of art. After his passing, several vintage old stock models were found at his warehouse. This is one of these rare finds.