These were designed to fit into sheath built into clothing so they would match the body contour. Mr Thompson notes he has only ever seen 2 of these, this being one of those. Marked DND and P on the reverse. DND is the mark of the New Zealand Defense Department Purchased From author Leroy Thompson and comes with a COA. From an article written by Leroy Thompson for Tactical Knives magazine (March 1997): Because most clandestine blades were manufactured on a custom or semi custom basis, variations will be as diverse as the imagination of those who carried them. A few examples, for instance, had curved or angled blades to fit the contour of the body better, much as Gerber angled the blades on the earliest Mark IV.