New set of heavy duty riser gaskets for all common log style exhaust manifolds. 1/8" thick material for extra sealing power. Highly suggested to use RTV silicone when installing these riser gaskets. 5" OD X 3" ID, standard 4 bolt pattern. Fits Glenwood, Nicson, Hardin, Harman, Panther, Edelbrock and other log style manifolds. There are some odd sized log manifold flanges out there, so please be sure to check your flange dimension. Sold as a set.