The M2.0 Compact 4-inch with S&W's proprietary Armornite nitride finish on the stainless steel slide — a surface-hardening treatment that provides corrosion resistance comparable to stainless at lower weight than stainless slides. Type: Pistol Action: Semi-Automatic Caliber: 9mm Capacity: 15 Year introduced: 2020, USA Weight: 24 oz Overall length: 7.3" Status: Active Intended use: duty, concealed_carry, law_enforcement