The Agency Arms 417 Compensator features a 2 chamber design (2 vertical ports and 2 side venting ports), it also features a front sight hole. The Agency Arms 417 Compensator is threaded with the standard 1/2x28 thread pitch (Overall barrel protrusion should be 0.715" +/- 0.005" for optimal fitment). It features a 2 chamber design (2 vertical ports and 2 side venting ports. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.