Safariland 6305 ALS Tactical Leg Holster with Detachable Leg Harness, Black, STX, Glock 21 with M3 ALS (Automatic Locking System) secures weapon once Holstered. Low-Ride level Simple Straight up Draw after deactivating the release Standard double strap leg shroud with mounting holes for optional accessories Safari laminate Thermal Molded construction protects the handgun and sights (ALS ) Automatic Locking System secures weapon once holstered (includes SLS hood assembly and Hood Guard) Adjustable vertical leg strap, standard double leg strap and leg shroud with mounting holes for optional accessories Simple straight up draw once all releases are de-activated Mounted to the same leg shroud assembly as the popular 6004 series Adjustable vertical leg strap with quick release detachable leg strap