Order 4" Ocal PVC coated conduit and get the best quality stuff out there. Ocal by Thomas & Betts meets the highest specs of any comparable coated conduit on the market, and it is the only one that is UL-6 Listed! Ocal 4" conduit begins with a rigid aluminum base which is cleaned and coated inside with 2 mil of blue urethane. The threads are also coated urethane and the outside is coated in 40 mil PVC. Talk about corrosion protection! See our whole selection and get a quote/place an order with us today.