Vibrant 3-Bolt T304 SS Exhaust Flanges (3in I.D.) - 5 Flange Bulk PackVibrant Performance Stainless Steel Exhaust Flanges are available in sizes ranging from 2* to 4* I. D. and a choice of 2 and 3 Bolt configurations. All Flanges are 3 8* (10mm) thick. They can be purchased individually or in cost effective boxes of 5. Vibrant Performance also offers a 4 Bolt flange for oval tubing in sizes ranging from 3* to 4* nominal oval size. Exhaust Flange; 3 in. ID; 4. 375 in. Flange W; 4. 3125 in. Flange H; 0. 375 in. Thickness;