Gen4 G21 Short Frame variant with a reduced-circumference grip achieved through the small backstrap insert. The SF designation specifically indicates the Gen4 G21 configured with the smallest backstrap option, reducing trigger reach for smaller-handed shooters while maintaining full 13-round capacity. Type: Semi-Automatic Pistol Action: Striker-Fired Caliber: .45 ACP Capacity: 13 Year introduced: 2010, Austria Weight: 26.46 oz Overall length: 7.59" Status: Discontinued Intended use: service, law enforcement, duty