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 approximate 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.