The CARVER Custom 2 Port Compensator that's universal, allowing one compensator that fits all generations of Glock handguns. In addition, any other 9MM barrels cut for most suppressors with 1/2 x 28 threads will work with this compensator. Tame the recoil and muzzle flip of your 9MM with a CARVER Custom 2 Port Decelerator Aluminum Comp. The Decelerator includes 2 ports on top with 1 port on each side, totaling 4 ports to equalize the muzzle of your Glock or other handgun. The 2 Port version is recommended for use with Glock 34 slides or G17 if you are planning to shoot light 115 grain factory ammunition. Thread size currently for LoneWolf and other branded barrels in 1/2 x 28 tpi. Easy installation with use of a set screw or not. Designed for 1'st, 2'nd, 3'rd and 4'th Generation* Glock Models The guiderod channel, available on our other CARVER comps has been removed for this model. A setscrew is available on the bottom of the compensator but is NOT intended to be used for installation of the compensator. Due to vibrations, the setscrew will not hold the comp sturdy on the barrel. We recommend the use of red loctite #272 or Vibratite 123 for easy and dependable installation. With the use of any of our "very efficient" compensators, you will need to use a lighter recoil spring. If you are using factory loads or equivalents, your choice of either an 11lb to 13lb spring will be necessary. Uncaptured guiderods with Wolff springs provide less stackup when the slide is pushed to the rear from recoil and work best with light target loads.