Straight Stop Valve 5/8″ OD 5/8″ OD x 1/2″ OD (1/2″ x 3/8″ PEX) Reducing Stop Valve The PEXtite fitting is a unique combination of superior materials to meet the rigorous demands of the marine and recreation vehicle. Vibration and temperature swings must be prime consideration when developing products for these areas. Salt water exposure and ambient temperatures from -20F to +180F degrees are common experiences. Either pounding and choppy water at sea or backcountry roads, the system must maintain a seal for the integrity of the system. The PEXtite fitting materials were selected to ensure maximum strength and integrity. The body material is Polysulfone, PSU with properties that best match the requirements of the market. The 360 degree Grip-ring is marine grade 316 stainless steel. The seals are specially selected FDA approved EPDM rubber to complement the duty cycle and life requirements of the marine/RV water system. Use USA inch size, certified PEXtite or CSA listed, Pex tubing, for hot and cold fresh or salt water systems.