This is the Olsen OK 152 pocket knife made in Seki, Japan between circa 1978-1982. In the late 1970s. It is a factory sample prototype and still has the factory stickers on the handle. Olsen teamed up with Seizo Imai to produce models in Japan and this was one of these knives. Acquired direct from the closed factory of Seizo Imai and in storage for decades. Comes with Olsen box (may not be the correct one for this model).