This tubing meets the standards for NSF 51, 61, has a length of 250 feet, a maximum operating pressure of 180 psi and is designed for the following applications: air, water. It is blue, has an operating temperature of -68 Degrees F to 140 Degrees F and is resistant to abrasion, wear and is made of polyurethane. In addition, it has 6 mm outside diameter, 4 mm inside diameter, with a metric system of measurement, with 1 mm wall thickness, and Shore A 98 hardness.