The 6360RDS holster is specifically designed for firearms with red dot sights mounted to them. This holster with the Automatic Locking System (ALS?) builds on the foundation of the Self Locking System (SLS). It locks the weapon in all directions upon holstering, its operable with the thumb, and the weapon can be drawn straight out of the holster with no twisting required. ** Safariland? cannot guarantee that RDS holsters will be compatible with non-factory (Glock MOS, M&P CORE, etc.) mounted red dots. Numerous variables including depth of RDS into slide, use of dovetail, placement on slide, etc. can all affect the fit of the holster. This holster is not compatible with the Trijicon SRO optic.