OD is outside diameter of the tube. ID is inside diameter of the tube, not the Length. The thickness of tube = ( OD - ID ) / 2 Specification: Meets Food Sanitation Act Heat-resistance Easy disposal low odor and oil-resistance Flexibility Uses: Food tube products; Food Machinery connecting pipe; Liquor connecting conduit; Water dispenser, coffee maker, water heaters, rice cookers and other connecting pipes, conduits; Electrical equipment, such as the casing.