Description: This air filter is precision machined with stable characteristics and high reliability, which is a direct replacement with those who use an afterrmarket intake sytem. Specifications: Bottom diameter: 12mm Material: Metal Application: Update accessories Package Included: 1 set * Air Filter Notes: 1. Please allow 0-1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from real object.