Midwest Industries Muzzle Device Collar Features The Midwest Industries Muzzle Device Collar is machined from 4140 steel a material chosen for its strength and resistance to the stress of repeated firing cycles. It converts a SIG tapered barrel profile into a 90 degree shoulder which is the shoulder style most aftermarket muzzle devices are designed to index against. Without this collar a tapered SIG barrel cannot properly headspace many standard muzzle brakes or compensators. By correcting the shoulder geometry this collar opens up compatibility with a much wider range of muzzle devices for the MPX 9mm platform. A phosphate finish is applied to resist corrosion and wear from the heat and gas exposure that occurs at the muzzle during firing. The collar is made in the U.S.A. reflecting Midwest Industries manufacturing standards for its accessory line. Because it is purpose-built for SIG MPX 9mm models it installs with proper fitment rather than requiring improvised shimming or modification. This collar is a practical upgrade for MPX 9mm owners at GrabAGun who want reliable muzzle device compatibility on their factory barrel. Midwest Industries Muzzle Device Collar Specifications Manufacturer: Midwest Industries Model: Muzzle Device Collar for Sig MPX Material: 4140 Steel Finish: Phosphate Country of Origin: Made in the USA Caliber: 9mm Available At: GrabAGun