Heavy wall, bondable, drain system and all components are made from rigid PVC, proven in years of outdoor applications with lasting beauty. Clean-outs adapt to 1½” threaded (purchased locally) or connector (supplied) for end clean-outs with either threaded or slip end cap. Should a surface clean-out hole be desired, simply drill a 1” hole and snap in our clean-out fitting. To clean, remove plug and flush with hose. There are two supplied in every carton.