These metric nitrile "O" rings are used to create a tight seal when used in plumbing, hydraulics, air & other industrial applications. They are resistant to extreme changes in temperature, air, water, petrol & its various production forms, natural gas, silicones & solvents. They are supplied in a storage box & are ideal for workshop & 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