The PETOL SIGHT GLASS allows the pumper and water hauler to see what is flowing through drain lines at all times. The clear view nipple is made from a tough, shatter-resistant polycarbonate. This type of plastic has more than 30 times the impact resistance of safety glass, withstands prolonged exposure to ultraviolet rays, and can be used in temperatures ranging from -150° to 165°F. Specifications: Size (O.D. x L): 4" x 8" Wall Thickness: .500 Connection: Victaulic Groove Weight: 2-1/4 lbs.