The FN 509 Compact is built on a compact polymer frame that is aggressively textured to ensure an unyielding purchase on the pistol during rapid fire. Slide and barrel have also had their dimensions reduced to enhance the concealability of the 509 platform. The pistol is 9mm and striker-fired with 3.7-inch barrel, standard 12+1 capacity and the capability to accept all higher capacity FN 509 magazines. The patented FN Low-Profile Optics Mounting System accepts nearly all commercially available miniature red dot optics and features blackout iron sights that co-witness. The improved controls aid in manipulation, the new improved texturing on the two included backstraps provides better recoil management, and a new flatter faced trigger allows for more controllable trigger press and cleaner break.