STI Tactical 4.15 double-stack 1911 in 9mm with 4.15-inch barrel. Type: Pistol Action: Semi-Automatic Caliber: 9mm Capacity: 16 Year introduced: 2007, USA Weight: 36 oz Overall length: 7.5" Status: Active Intended use: Tactical 4.15 provides duty-grade capacity in a Commander-length form.