Safariland 6354RDSO ALS Tactical Holster, Fits Glock 19MOS with X300, Matte Finish, Ranger Green, Laminate Construction, Right Hand 6354RDSO-2832-721-MS19 The 6354RDSO holster is designed for firearms with red dot sights. Its Automatic Locking System (ALS) secures the firearm. Unlike Safariland's RDS series, the RDSO has an open pocket that protects the optic and does not use a flip-up dust cover.