The FN 509 Midsize MRD is a striker-fired 9mm pistol designed for concealed carry and everyday use. Its midsize polymer frame and 4-inch steel barrel provide a practical balance of shootability, concealability, and recoil control. The FN Low Profile Optics Mounting System supports direct mounting of a wide range of miniature red dot optics, while co-witness iron sights provide a dependable aiming solution. Textured interchangeable backstraps help tailor the grip to the shooter, and the flat-faced trigger delivers a consistent, controllable press. The pistol includes two 15-round magazines and features a Picatinny accessory rail for compatible lights and accessories.

Key features

• Optics-ready slide with the FN Low Profile Optics Mounting System for compatible miniature red dot sights
• 4-inch steel barrel and 15+1 capacity suited to everyday carry and practice
• Textured polymer grip with interchangeable backstraps for a more secure, adaptable hold
• Flat-faced trigger designed for a consistent and controllable trigger press
• Co-witness iron sights provide a backup aiming system
• Integrated trigger safety helps prevent unintended discharge from trigger contact alone

The FN 509 Midsize MRD combines practical carry dimensions, optics compatibility, and adaptable ergonomics in a dependable 9mm pistol.