Junio 240SRX-Ring Joint Gasket is t he same in design to the RX Ring . To distinguish from Junio 240RX-Ring Type Joints JUNIO SRX Ring Joint Gaskets are manufactured in different solid metal types like soft iron/SS304/316/321 metal and other alloy items. the suffix s is used to indicate the additional pressure passage hold in the ring cross section. This is to indicate the additional requirement to prevent pressure lock when connections are made up underwater.