The Apex Action Enhancement Kit for the FN 509 model pistols is a direct drop-in replacement of the factory polymer trigger, trigger bar, and sear. The patent-pending Apex design reduces trigger pull weight to give you an approx. pull weight in the 5.5 lbs range. Trigger travel is also reduced, including pre-travel, over-travel, overall trigger travel, and trigger reset distance. It provides a smooth uptake while delivering a crisp trigger break.