The Apex Extended Mag Release for the FN 509 model pistols is single side activated and a direct replacement for the factory magazine release. It incorporates an extended length to the mag release button and improves performance by making it easier to engage and release a magazine. Machined from bar stock steel, fully heat treated and finished in Black Oxide. Available in right and left hand. Expected Results: Direct drop-in replacement of factory magazine release Uni-directional - Choose Left Hand or Right hand based on your shooting hand. Angled and serrated face for easier mag releases. Easy to install Applicable To What Guns: For use Mfg: Apex Tactical Specialties Inc