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.Finish: BlackModel: Action EnhancementMaterial: Aluminum