This is a 20" (approx.) pipe sleeve for poured walls and barriers. Used to create openings for pipe to run through, wall sleeves are traditionally metal, but this sleeve is made of HDPE for quick and easy install and impressive strength under pressure. Additionally, polyethylene stands up well to acids, alkalies and other solvents.Model: CS-20, Material: HDPE, ID (in.): 19.12, ID (mm.): 485.6, lbs: 17.5, Kg: 7.94