Uni Filter Features & Benefits: Improved performance through increased airflow :: Improved protection through finer filtration levels :: Substantial cost savings through serviceability and re-use. Ideal for servicing filters on long, dusty trips. Replace and clean and you're good to go. Uni Filter replacement automotive air filters are designed to give the ultimate in protection while delivering the best performance possible. Uni Filter radial filters have two layers of foam. The outer Yellow layer is the work stage and inner green layer is safety stage for extreme dusty conditions. Layers can be removed for easy servicing. Designed and made in Australia for Australian conditions.