Features: 1. Aluminum gaskets ensure alignment and spacing between components. 2. Stable rigidity is strong. 3. Lightweight, non-magnetic and resistant. 4. Made of high quality aluminum, to use. 5. Fine workmanship makes sure good performance. Specification: Length: about 40mm/1.57inch Outer diameter: about 10mm/0.39inch Material: aluminum Color: silver Package List: 8 * Aluminum Gasket 40mm