Vibrant Titanium 2-Bolt Flange - 2.5in IDVibrant Performance 304 Stainless Steel 2 Bolt Exhaust Flanges for round tubing are available in a variety of sizes ranging from 2 in. to 4 in. I. D. Matching gaskets are available, manufactured from multi layer Graphite material. Exhaust Flange; 2. 5 in. ID; 5. 25 in. W; 3. 5 in. H; 0. 3125 in. Thickness; Titanium; 2 Bolt; 4 in. Wall Thickness;