The Model 578 GLS Pro-Fit brings the unique GLS (Grip Lock System) and SafariSeven together in a holster designed to fit a wide variety of guns. The Pro-Fit is customizable and adjusts to securely fit over 225 firearms. The 578 also features the GLS, an innovative technology that automatically secures the weapon when holstered and releases it upon application of the middle finger with a standard shooting grip for a more intuitive and safer release. The holster body is constructed with SafariSeven, a lightweight, state-of-the-art nylon blend is completely non-abrasive to a guns finish, tolerant of extreme high and low temperatures, and easy to maintain. This holster includes an injection-molded paddle and an injection-molded belt loop that is adjustable for maximum comfort.NOTE: This is a multi-fit holster, not all gun/optic variations will work in the holster. If the optic is mounted too far forward it will prevent the firearm from seating into the GLS mechanism. Common firearms that will not seat properly are the Staccato P/C2 and the Springfield Prodigy. If you have questions on your specific combination please contact customer service.