Herrington Arms HC509 FN 509 Compensator Black. It is made of high-quality 7075 aluminum and coated with either FDE Cerakote or Black Anodized finish to compliment your specific 509 configuration. The HC509 will work with the stock springs provided your gun has gone through recommended break in period of 500 rounds factory new ammunition is used with the threaded barrel you intend to use with the firearm before installing a compensator. Fits on 1/2-28 threaded barrels and most aftermarket barrels. Eliminates approximately 20percent of muzzle flip. Specifications for Herrington Arms HC509 FN 509 Compensator: Manufacturer: Herrington Arms Fabric/Material: 7075 Aluminum Gun Make: FN Herstal Gun Model: FN 509 Features of Herrington Arms HC509 FN 509 Compensator NOT COMPATIBLE WITH BAR-STO KKM OR EFK BARRELS Works with 9mm models The HC509 Compensator passed our 4000-round testing sequence without any issues WE RECCOMEND SURPASSING THE 500 ROUND BREAK IN BEFORE INSTALLING THE COMP Blems are cosmetic ONLY. They will function as normal - May have nicks dings pitting machining marks chips discoloration etc. AMMO DISCLAIMER: We DO NOT recommend using plated bi-metal or frangible ammo in ANY of our compensators. Doing so will void the warranty and we will not cover or replace the comp if there are any damages. Package Contents: Herrington Arms HC509 FN 509 Compensator 5/64 Allen key Steel replacement 8-32 set screw What firearm models does the manufacturer say Herrington Arms HC509 FN 509 Compensator is compatible with? The manufacturer suggests that Herrington Arms HC509 FN 509 Compensator is compatible with FN 509Herrington Arms HC509-BL: HC509 FN 509 Compensator Black