These polypropylene fittings are used to connect tubing or hose to pipe. Each fitting has a serrated end for inserting into flexible hose or tubing and the other end is threaded with standard female pipe threads. A hose clamp is recommended for hose and tube connections. Meets FDA standards for this material. The size below indicates FNPT x Hose ID Size. Max continuous use temperature 220°F. Melt flow rate 230°C/2.16 kg - L.