Wilson Combat AR15 One Piece Stainless Gas Rings Stainless. Not only is it incredibly reliable but its solid stainless alloy construction also grants extended intervals of maintenance-free use. Easily replacing the traditional three-piece design this single helical coil of 300 series stainless steel wire sports a smooth outer diameter fit perfectly for AR bolts in direct Impingement designs. AR-15 Stainless one-piece construction for a long lifespan and improved gas seal Fits direct impingement AR-10 models only Package of 3 Specifications for Wilson Combat AR15 One Piece Stainless Gas Rings: Manufacturer: Wilson Combat Color: Stainless Features of Wilson Combat AR15 One Piece Stainless Gas Rings Achieve a superior gas seal between your AR-15 bolt and carrier with the one-piece gas ring. Not only does it boast improved reliability but its hardened stainless alloy construction also allows for extended maintenance intervals. Package Contents: Wilson Combat AR15 One Piece Stainless Gas Rings Wilson Combat TR-HGR-15: AR15 One Piece Stainless Gas Rings Stainless