Anarchy Outdoors HK VP40/VP9 Compensator Purple. The compensator attaches to the muzzle allowing the gasses to combat recoil without sacrificing shot power. It helps you get back on target for a quicker follow-up shot. This product is not manufactured authorized endorsed or warranted by Heckler & Koch. Specifications for Anarchy Outdoors HK VP40/VP9/VP9 SK Compensator: Manufacturer: Anarchy Outdoors Caliber: 9mm Luger Gun Make: Heckler & Koch Features of Anarchy Outdoors HK VP40/VP9/VP9 SK Compensator Reduces kickback by up to 50percent by pushing down the muzzle and redistributing gas pressure; Does not sacrifice shot power; Helps reduce the time between shots; Easy installation Package Contents: Anarchy Outdoors HK VP40/VP9/VP9 SK Compensator What firearm models does the manufacturer say Anarchy Outdoors HK VP40/VP9/VP9 SK Compensator is compatible with? The manufacturer says that Anarchy Outdoors HK VP40/VP9/VP9 SK Compensator is compatible with Heckler & Koch VP9 SK Heckler & Koch VP9 Heckler & Koch VP40Anarchy Outdoors 791617487345: HK VP40/VP9 Compensator Purple