Safariland 6390RDS ALS Hardshell STX OWB Belt Holster Glock 19 Gen 3 G19 Gen 4 Left Hand OD Green. This open-top holster features the Automatic Locking System (ALS) an internal locking device that retains the weapon in all directions with no straps or snaps to manipulate. Once the weapon is holstered it locks into place. The holster is completely operable with the thumb and once the ALS is deactivated a simple straight-up draw is used. Features a mid-ride belt loop that is rides close to the body. Specifications for Safariland 6390RDS ALS Hardshell STX Glock 19 Gen 3 G19 Gen 4 OWB Belt Holster: Manufacturer: Safariland Color: OD Green Gun Make: Glock Gun Model: Glock 19 Gen 4 Glock 19 Gen 3 Holster Type: Belt Holster Holster Material: Hardshell STX Attachment Type: Mid-Ride Finish: STX Tactical Application: Duty Age Group: Adults Retention Level: Level I Package Contents: Safariland 6390RDS ALS Hardshell STX Glock 19 Gen 3 G19 Gen 4 OWB Belt Holster What firearm models does the manufacturer say Safariland 6390RDS ALS Hardshell STX Glock 19 Gen 3 G19 Gen 4 OWB Belt Holster is compatible with? The manufacturer says that Safariland 6390RDS ALS Hardshell STX Glock 19 Gen 3 G19 Gen 4 OWB Belt Holster is compatible with Glock 19 Gen 3 Glock 19 Gen 4Safariland 1315058: 6390RDS ALS Hardshell STX OWB Belt Holster Glock 19 Gen 3 G19 Gen 4 Left Hand OD Green