The Underworld Arms P80 G17 Stand Off Compensator is the perfect addition to your Polymer 80 PF940V2 9mm or .357 pistol. The quad port design greatly reduces muzzle flip and felt recoil and gets you back on target fast for shorter split times and improved battlefield effectiveness. The stand off design prevents the slide being pushed out of battery in close quarters engagements.  The mil spec hardcoat anodized matte black finish protects the CNC machined 7075 T6 compensator from wear and reduces the visual footprint.   Unlike other stand off compensators the UA P80 Stand off Comp is a one piece billet design that mounts to your frame with two locking screws taking advantage of the P80s lower rail. The UA Stand Off Comp includes a removable lower rail for mounting lights and accessories.  The UA P80 G17 Stand Off comp is only compatible with the P80 PF940V2  G17 frame, it will NOT fit on factory glock frames or any other frame.  Check your P80 for frame sag before ordering, this can be caused by baking the frame after cerakoting, out of spec locking blocks, or drilling holes slightly out of place. If the front of your slide is more than .05 from the frame do not use this Stand Off Comp.    Tech Specs Material: 7075 T6 Finish: Mil Spec Hardcoat Anodized Matte Black Thread Size: 1/2x28 Caliber: 9mm Luger and .357 Only Weight: 3.02oz Overall Length: 3.21" Length From Slide .826"   General Compensator FAQ Compensators function by redirecting exhaust gas up and to the sides, this means there is less felt recoil energy for the shooter and less muzzle flip. Because there is less recoil energy with a compensator you may need to use a lighter recoil spring for your gun to cycle correctly. In most cases the stand off comp will cycle with a stock spring even with low power 115gr target ammo, however certain combinations of slides/optics/barrels may require you lower your recoil spring weight. If you experience FTE or FTF after attaching a compensator this usually means you need a lower lbs recoil spring.  Firearms in images are shown for illustrative purposes only, they are not included with the compensator.