B & K Toilet Tube - 3/8 In. toilet PEX riser. PEX construction with formed nosepiece to avoid stripping. Approved for residential, commercial, and industrial applications for water supply connections to fixtures. PEX can be cut to the desired length. Riser includes a delrin compression ring to help prevent leaks. NSF (National Sanitation Foundation) certified. Size: 3/8 In. OD x 12 In. or 20 In. L.