Single spiral of spring steel loops around the bolt three times and leaves no path for gas leakage. Replaces conventional three-piece "piston ring"-style sets that can accidentally line up, causing a major leak from the gas expansion chamber in the carrier.
AR-15, Issue:09, Page:011
Big Book Catalog, Issue:66, Page:011
Law Enforcement / Police Store, Issue:09, Page:006
New Product Supplement, Issue:563, Page:006
SPECS: Polished spring steel.