If you are referring to being able to "tune" a brake there are several offerings, APA being a great one. But if you are considering one like the Savage or Brockman that simply allows you to turn it "On or Off", I'd say save your money. There is typically so much carbon filth that will build up in the brake assembly, its unlikely to change position when you want it to. The carbon buildup and dirt from shooting will jam it up after some use. It is likely to also change your POI. With todays self timing brake attachment systems, most are quite easy to remove and install, and will give better results than most of these "open/close" models which are mostly of the radial design. Take it for what its worth, just one man's opinion.