These are Schedule 40 and Schedule 80 PVC socket fittings. Schedule 40 is NSF listed, has a 33° F - 140° F working temp, and is available in gray and white. Schedule 80 is also NSF listed, has a 33°F - 140° F working temp, and is available in gray. For UV resistance of PVC pipe and fittings, paint with a white water based latex paint. Both have a wide variety of uses in the chemical field and industrial plants, just to name a couple. All Schedule 40 socket fittings are manufactured in strict compliance to ASTM D 2466. All Schedule 80 socket fittings are manufactured in strict compliance to ASTM D 2467. PVC Schedule 40 and 80 fittings are produced from PVC Type I, cell classification 12454, conforming to ASTM Standard D 1784.