LanTac 9INE Professional upgrade drop in barrel is match grade and precision machined from 416R stainless steel. It also has 6 grooves, is cut rifled, and has a 1:10 twist rate. The barrel is also bead blasted to create a satin finish prior to plating. This model fits a Glock 17, is fluted/threaded with 1/2-28 TPI threads, and has a bronze finish.