Nickson Exhaust Pipe Flange Gasket - 31718 Part #: 31718 Line: NIC Nickson Exhaust Pipe Flange Gasket Manufacturer's Defect Warranty Material: Metal Quantity: 1 Inside Diameter (in): 2-3/4 Inch Thickness (in): 15/16 Inch Bolt Hole Diameter (in): 1/2 Inch Number Of Bolt Holes: 3 Bolt Hole Center To Center (in): 3-7/8 Inch Number Of Port Holes: 1 Show More Show Less