4.75 threaded Apex Tactical barrel. It has been tested in a couple M&P's and functions perfectly.
Some minor fitting may be required. The item "Apex Tactical Smith & Wesson M&P 9mm 4.25 threaded barrel" is in sale since Wednesday, October 04, 2017. This item is in the category "Sporting Goods\Hunting\Gun Parts\Pistol".The seller is "kristian5337522" and is located in Uniontown, Ohio. This item can be shipped to United States.