Blackhawk's Serpa CQC Concealment holsters with patented Serpa Auto-Lock technology, the holster delivers a smooth draw, easy re-holster and unparalleled handgun security that is perfect for concealed carry. Features passive retention detent adjustment screw. Includes Belt Loop Platform and Paddle Platform. Fits Shoulder, S.T.R.I.K.E., Quick Disconnect and Tactical Holster Platforms. This model is compatible with Glock 20, 21, 37; S&W M&P 45, S&W Performance Center M&P 9/40.