jacket pocket. While some of the cheaper semi-auto pistols are best carried with an empty chamber, higher-quality pocket pistols are designed to be carried with a round chambered and with the safety engaged (ON). Many older pistols (and even some revolvers) also had grip safeties for additional security. However, the newer double-action-only pistols are made without manually operated safeties, but with a long and heavy trigger-pulls – similar to revolvers. Pocket holsters are highly recommended for the safer carry of pocket pistols, with the standard practice being to carry the holster (sometimes with a second magazine sub-pocket stitched into the holster) in a front or rear trouser pocket with nothing else carried in the pocket that could snag on the gun when drawn. The most popular pocket holster designs are typically made of form-fitted leather, with a heavy layer of leather worn outward from the body to prevent printing of the gun outline on tight clothing, although Kydex holsters are also used, especially for thicker pocket pistols for which the added thickness of a leather holster would cause an excessive overall thickness. The use of moisture and vapor-barrier layers in the holster stitched closer to the body is recommended to prevent damaging the finish of the pocket pistol due to sweat. This extra layer also serves to increase carry comfort and to prevent chapping or blistering the skin under the holster due to repetitive motion rubbing or friction that can occur while walking, jogging, or running. Pocket pistols are derided by some gun enthusiasts who claim that they provide inadequate self-defense due to their small size, small caliber, and poor sights. Still, the numbers sold speak of a wide degree of popularity, with some models having been sold in quantities in excess of 3 million over 30 or more years. Models Semi-automatic pistols AMT Backup Beretta 21 Bobcat Beretta 418 Beretta 950 Beretta 3032 Tomcat Beretta 1934 Beretta 1935 Bersa Thunder 380 Bryco Arms Colt Model 1903 Pocket Hammer Colt Model 1903 Pocket Hammerless Colt Model 1908 Vest Pocket Diamondback DB9 FN Model 1903 FN Model 1905 FN Model 1910 FN Baby Browning Heckler & Koch P7 Kahr P380, P9, P40, P45 Kahr K9 Kahr CW380 Kahr CW9 Kahr MK9 Kahr PM9, PM40, PM45 Kel-Tec PF-9 Kel-Tec P-11 Kel-Tec P-32 Kel-Tec P-3AT Kevin ZP98 Kimber Solo Korovin pistol Glock 26, 27, 36, and variants Makarov pistol North American Arms Guardian