Nylon reinforced. FDA compounded PVC for pressurized drinking water systems, etc. No taste or odor. #164 “Cold Water”. Max W.P. depending on I.D. size @ 70°F (21°C): #164=150 PSI (1.03 Mpa). Operating temperatures +20° to +150° F (-7° to +66°C). NOT RECOMMENDED FOR BELOW WATERLINE THRU-HULL CONNECTIONS. CA prop 65 Compliant.