The Glock 21 Gen4 in .45 ACP was adopted by select law enforcement agencies and special operations units preferring the .45 ACP cartridge in a high-capacity polymer pistol. Features the Gen4 improvements in a full-size .45 ACP platform. Type: Semi-Auto Pistol Action: Striker-Fired Caliber: 45 ACP Capacity: 13 Year introduced: 2013, Austria/USA Weight: 29.3 oz Overall length: 7.6" Status: Active Intended use: Law Enforcement, Duty