The Flexseal Adaptor Coupling is a stepped molded rubber sleeve that has different diameters at each end. The Flexseal Adaptor Coupling provides an efficient method of connecting pipes that have varying outside diameters. Please note, adaptor couplings should not be used on water company owned pipes, to connects to water company regulations a Flexseal Standard Coupling (shearbanded) must to be used with a bush or multibush if a step is required.