Fortis Manufacturing, Inc., Muzzle Brake, Fits 300 Blackout through 7.62X39, Threaded 5/8X24, Black Color, Nitride Finish, Includes Crush Washer, Compatible with Fortis Control Shield WARNING: This product can expose you to chemicals including arsenic, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov 4140 Steel Nitride coated Compatible calibers: 300BLKOUT, 6MM ARC, 6.5 Grendel, 6.8 SPC, 300 HAM'R, 7.62x39 5/8 x 24 TPI Comes with a crush washer 2.8 ounces 2.28 inches Made in America Fortis Control Shield compatible The new Fortis Muzzle Brake was inspired by the sharp lines of their brand. Like many of Fortis' products, the machining on this brake takes a lot longer than the competition. Fortis takes their time to create the very best products out there. Try this new muzzle brake once and you'll be glad you did. The performance is unmatched and muzzle rise is non-existent. Keep your speed and accuracy up. Put more down range and on target.