STI Duty One in 45 ACP. Duty-configured 2011 platform with 4.5-inch barrel and fixed sights. The 45 ACP variant was produced for agencies and individuals who required 45 ACP performance in a double-stack format. Less common than the 9mm Duty One. Type: Pistol Action: Semi-Automatic Caliber: 45 ACP Capacity: 14 Year introduced: 2012, USA Weight: 36 oz Overall length: 8.25" Status: Discontinued Intended use: Duty, Service, Law Enforcement