This 20th Anniversary model is a SCUBA/DEMO knife that’s a reproduction/replica of one of the rarest Vietnam military knives ever made to date. Of the original batch of 39 knives made, only 1 out of the lot has survived till this day. SOG has revived this knife by producing a copy that is made as close as possible to the original knife, except for a few shape changes. The fact that it is sharpened on both sides makes it illegal to own in some states and countries. It can’t really be classified as a ‘dagger’ because the area forward of the serrations (aka teeth) is not sharpened. So basically it is a normal knife with sawback teeth on the other side, much like a Rambo style knife. This very design is a very unique and purposeful one, and an interesting one at that. Originally designed during the Vietnam War era diving knife, the Scuba/Demo has a straight edge to cut, and a serrated edge to saw through thick rope. Nevertheless for those lucky enough to own it, it is a sight to behold. IMHO leather handles with brass makes this knife a very handsome and classic ‘Vietnam era’ knife. Another must have in the SOG collection. It is also the only old model that has its model name engraved on the knife – “SCUBA/DEMO” on center right of the blade. *Rarity Note: Due to the 20th Anniversary model being only produced for one year it is exceptionally hard to find today.