The Polish Knife Maker Jakub Wieczorkiewicz manufactures tactical pocket and fixed knives under the brand Poltergeist Works from high-quality materials. Almost all individual parts are manufactured completely by hand, without modern production techniques such as CNC, WaterJet or laser. The components he uses are made exclusively of high-end materials. For example, only powder metallurgical steels are used for the blades of his pocket knives.