The MCS Glock 19 Gen 1-4 N3 Black Nitride fluted barrel provides superior USA made quality and performance at a affordable price. This barrel is an aftermarket direct OEM Plus 1:1 replacement. Machining, craftmanship and finish accurately applied to ensure a no issues drop-in replacement upgrade to your pistol. No gunsmithing or fitment is required for slides that meet or exceed OEM specifications. Durability and longevity are provided by the 416R Stainless steel 1:10 twist rate rifling to ensure you remain on target for follow up shot after follow up shot for years and many rounds down the range.