Rubber seal rings set: this set contains 520 pieces of different sizes rubber grommets, packed in a clear plastic organizer case with snap close lid, portable and easy to store Quality material: made of flexible and durable rubber, and are of good electric resistance capability, seal rings will fit those drill holes precisely and efficiently Convenient to use: o rings are designed for easy installation and click snap affixing drill holes, metal panels would create a neat finished look on furniture and electric boxes They can be produced in many different types of rubber, for various industrial and anti-vibration purposes These handy grommets are great to have around the house for leaky faucets, hoses and more. These harness grommets protect wires and harnesses as they pass through sheet metal, firewalls and truck beds Material: rubber Color: black Set includes rubber grommets: m3- 50pcs, m4- 50pcs, m5- 50pcs, m6- 50pcs, m8- 20pcs, m10- 20pcs, m12- 20pcs Package Contents: 520pcs x Rubber Grommet Only the above package content, other products are not included Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm