FN 509 Features The FN 509 is built on the proven architecture of the FNS Compact FN made changes internally and externally to meet the rigorous performance standards of the MHS requirements and further developed the platform into the FN 509 with the help from industry experts. This model features 4 cold hammer-forged stainless steel barrel combat-style sights and improved front and rear cocking serrations. The FN 509 also features a MIL-STD 1913 accessory mounting rail and interchangeable backstraps. It has a double action operation fully ambidextrous slide stop lever and magazine release as well as fixed 3 dot luminescent sights. This model also features a polymer construction with replaceable steel frame/slide rails. FN 509 Specifications Brand: FN Model: 509 Caliber: 9mm Luger Frame Finish: Flat Dark Earth Action: DAO Barrel Length: 4 Slide Description: Flat Dark Earth Steel Capacity: 17+1 Frame Material: Polymer Grips: Flat Dark Earth Interchangeable Backstrap Height: 5.56 OAL: 7.40 Safety: Manual Sight Configuration: 3 Dot Combat Sight Style: Fixed Twist: 1:10 Weight: 26.90 oz Width: 1.35