Compatibility: Red Dot Sight and Compact Light for most fits Retention System: ALS? (Automatic Locking System) allows straight-up draw motion Design: Open-top for quick weapon retrieval without SLS Construction: Two-piece reinforced holster body for increased strength Front Sight Channel: .350 in; Glock 17/19 and similar models have a front sight clearance of 0.50 in The Safariland Solis Holster combines the security of ALS with the release speed and draw simplicity of an open-top design. Solis is compatible with most compact red dot sights and subcompact lights. The ALS secures your weapon automatically as it is holstered, yet still allows a fast, natural draw with the swipe of the thumb release as you acquire your shooting grip. Built from durable, weather- and temperature-resistant SafariSeven non-marking nylon blend, Solis will not scratch or mar the finish of your firearm. The holster*s open muzzle end design allows for easy debris removal or accommodates threaded barrels.