 The Pistole 04 was later updated with a coil mainspring to Model 1906 pattern as Luger continued to refine and improve his design.Georg Luger introduced a new version of the Parabellum pistol in 1906, which would become known as the Model 1906 or "New Model" ("Neues Modell").This latest version of the Parabellum replaced the old flat laminated main spring with a new, more reliable coil design.