It is ready to use and will give you easy access and storage to whatever size you need. The storage posts are clearly labeled.

O-ring Kits/ O-ring AccessoriesThe convenient O-Ring kit contains 30 of the most popular sizes, for a total of 380 O-Rings, in one convenient kit. It is ready to use and will give you easy access and storage to whatever size you need. The storage posts are clearly labeled to provide instant size identification. A wide range of quality o-ring kits/ accessories for customer option. Select the preferred international standard size, kits type or specific requirement for your sealing solution