Our M1A/M14 cleaning rod guide slips over the GI flash hider to maintain correct alignment of the cleaning rod with the bore. Fits up to 30 cal. rods such as the Dewey coated rods. Works for all calibers. Just slip the rod guide over your cleaning rod, then install your jag, or brush on the rod prior to placing the Muzzle Buddy on the flash hider. Our Muzzle Buddy comes with a solvent port for ease of use. This is the last rod guide you will need. Built to last a lifetime! The I.D. of the Muzzle Buddy is .725. It may not be compatible with all aftermarket Muzzle breaks.