These metric nitrile \"O\" rings are used to create a tight seal when used in plumbing, hydraulics, air and other industrial applications. They are resistant to extreme changes in temperature, air, water, petrol and its various production forms, natural gas, silicones and solvents. They are supplied in a storage box and are ideal for workshop and heavy industrial use. Inside Dia. Mm Section mm Qty 3.0 1.0 10 4.0 1.0 10 4.8 1.9 20 5.8 1.9 20 6.8 1.9 20 7.8 1.9 20 5.0 2.0 10 8.0 2.0 10 8.8 1.9 15 9.8 2.4 15 10.8 2.4 15 11.8 2.4 10 13.8 2.4 10 15.8 2.4 10 20.0 3.0 10 22.0 3.0 10 20.0 4.0 5 22.0 4.0 5