The Protech Razor Wire Skull TR-4 Automatic Knife (4" Black Plain Edge) Limited Edition. This is the Protech Barb Wire Skull TR-4 knife. It features a polished silver aluminum handle with a barb wire anodized theme and a Bruce Shaw designed sterling silver skull. The blade is black finished and marked "Ltd. Edition #** of 300" on the back side. Black finished hardware and pocket clip. Includes super durable nylon sheath.