Corrugated pipe and fittings are made from strong lightweight polyethylene plastic - won't break or crush and resists acids, alkalis, and freezing temperatures. Ideal for drainage and waste management. 3 In. size is 3 In. I.D. x 3-5/8 In. O.D. 4 In. size is 4 In. I.D. x 4-3/4 In. O.D. 10 Ft. lengths.