Rival Arms RARA20S201C Precision V1 Drop-In Barrel for 9mm Luger, 4.25" length, Bronze PVD finish, stainless steel construction (416R). Features 6-groove rifling with a 1:10 twist, low-temperature vacuum PVD coating for wear resistance, Boroslick Boron Nitride DCD inner bore treatment, and a target crowned muzzle. Fits S&W M&P (Except for M2.0). Not available to ship to California, Illinois, or Washington.