The John Guest range of CI and CM fittings are manufactured in white (for inch sizes) and grey or black (for metric sizes) acetal. With a food grade EPDM ‚O’ring they have been developed for the water industry but are equally suitable for other potable liquids. They are also recommended for intermittent hot water applications. The CI and CM range of fittings is NOT suitable for compressed air and vacuum applications. For these situations we recommend our PI and PM range.