The 6304RDS-SP10 holster is specifically designed for firearms with red dot sights mounted to them. This holster features the Automatic Locking System (ALS®). It locks the weapon in all directions upon holstering, it’s operable with the thumb, and the weapon can be drawn straight out of the holster with no twisting required. Additional retention is achieved when used with the SLS rotating hood. The 6304RDS-SP10 features the single strap leg shroud allowing the holster to be worn higher on the thigh. Suede lining helps protect the gun's sights and finish. ** 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.