This gasket is compatible with Hydro, Bazooka Farmstar and Cadman Shug Couplers. For the 6" gaskets, we incorporate our own gasket which has been designed for a tight fit seal even under low pressure.  This gasket is used on all of the Shug Grip Couplers that are 6" and smaller.  The 8" gasket fits the 7" and 8" Shug Grip Couplers.  Please check our our complete line of accessories for Shug Grip Couplers. Please be sure to order the correct size gasket for your needs.