The KickPort T-Ring has an outer diameter of 7.25-inches and an inner, port diameter of 5.25-inches. In addition to serving to reinforce bass drum head from tearing and splitting around the KickPort, the T-Ring can be used as a template for cutting a 5.25-inch port in any drum head for optimum miking in studio and live situations. The KickPort requires a reinforcement ring. Colour: Clear