The Apex Heavy Duty Striker for the FN 509 is a direct drop-in replacement option for customers with FN 509 and FNS series pistols. The striker is machined from a billet of stainless steel and heat treated for enhanced durability. Direct drop-in replacement of FN 509, FNS, FNS Longslide and FNS Compact striker Requires the following factory striker components: striker spring stop, striker spring stop pin, striker return spring and striker spring guide. Works on all currently available FN 509 models including the Midsize and Tactical Works in all FNS, FNS Longslide and FNS-Compact pistols Mfg: Apex Tactical Specialties Inc