Just for everyone's information, the Sigtac Pitbull is made by Timberline and is the same knife as the Timberline Lightfoot Mini-Pitbull. Instead of Impactguns' $40 price you can find both knives for $20 to $25 on the net.
Gun companies don't make knives, Glock being an exception. HK and Sig knives are almost always existing models from a knife manufacturer that has the gun company's logo on them. Sometimes different colors are used and sometimes, but very rarely, different materials are used.