Shop › APEX FN 509 ENHNCMNT TRIGGR KIT BLK APEX FN 509 ENHNCMNT TRIGGR KIT BLK $160.00 Apex Tactical Specialties Apex Enhancement Trigger Kit for FN 509 Black. 119-125 Quantity: Add To Cart Added! Apex Tactical Specialties Apex Enhancement Trigger Kit for FN 509 Black. 119-125