This set of O-rings contains the 18 most common sizes. The nitrile sealing rings are heat-resistant and resistant to most petroleum and silicone fluids and solvents. The O-rings are supplied in a resealable plastic case. This includes a list of contents for quick and easy identification. https://elecena.pl/product/18476175/has02-nitril-o-ring-set-225-pieces 2021-05-16 https://elecena.pl/product/18476175/has02-nitril-o-ring-set-225-pieces 2022-03-18 https://elecena.pl/product/18476175/has02-nitril-o-ring-set-225-pieces 2023-02-16 https://elecena.pl/product/18476175/has02-nitril-o-ring-set-225-pieces 2023-07-15