Alpha Wolf barrels establish the benchmark for absolute accuracy and combat reliability. It is the pinnacle of what every other barrel manufacturer strives to be.Barrel Features: PROUDLY MADE IN THE USA!! Fits Glock generations 1-4 Barrels do not fit Gen 1 "pencil barrel" G17's. Pencil barrels were included in serial numbers AA000-AL999 G17's Designed for lead, plated, or jacketed ammunition Certified, stress relieved 416 stainless steel Button rifled, three stage honed bore Industry recognized SBN premium coating (SBN is Salt Bath Nitride, similar to Tennifer) Heat treated to RC 40-42, then SBN coating increases surface hardness to RC 60 Exacting tolerances allow for drop in installation Fluting creates path for heat and debris to escape