With the new addition of the .45 AUTO in the Gen5 lineup, the G21 Gen5 MOS delivers improved accuracy, light recoil, and now has the option to install an optic. All of the Gen5 qualities are present in this compact-size pistol: The latest GLOCK nDLC surface finish, unmatched in hardness and rust resistance; the high traction Gen5 frame texture, quickly reversible magazine catch, ambidextrous slide stop lever, the GLOCK Modular Backstrap System (MBS) for individual operator adjustability, the universally-acclaimed GLOCK Safe Action System and high visibility orange magazine followers.