Oatey 41601 40 Mil, Gray, 6 x 50-Feet Economical, time-tested flexible pan liner. Available in 30 & 40 mil thicknesses. Liner marked in 6"" increments for ease of measuring. Dam corners available. Meets ASTM Spec. D4551. Superior cold weather characteristics. Videos Shower Pan Liner Installation Economical, time-tested flexible pan liner Available in 30 & 40 mil thicknesses Liner marked in 6-Inch increments for ease of measuring Dam corners available Meets ASTM Spec. D4551