These copper seal exhaust gasket are made from 0.043" solid copper and are racetrack proven to eliminate exhaust leaks in top fuel dragster, funny car, and alcohol class racecars. The dimensions of the port measure 1.5'' high by 1.5'' wide. They feature an embossed O-ring design to increase sealing pressure around the exhaust ports creating a tight, leak-proof seal. They are also ideal for motor homes and towing. They are sold as a pair.