Various PP series are manufactured in Germany, France and the United States. The Walther TPH pocket pistol is a smaller calibre pistol introduced in 1971 which is identical in handling and operation to the PPK. The series includes the Walther PP, PPK, PPK/S, and PPK/E models. It features an exposed hammer, a traditional double-action trigger mechanism, a single-column magazine, and a fixed barrel that also acts as the guide rod for the recoil spring. The Walther PP ( German: Polizeipistole, or police pistol) series pistols are blowback-operated semi-automatic pistols, developed by the German arms manufacturer Carl Walther GmbH Sportwaffen. Fixed iron sights, rear notch and front blade