Pro DRY S Air Filter by aFe. The Pro DRY S is the perfect combination of performance, protection and convenience. When you want increased airflow with superior filtration, but ease of maintenance is a high priority, look no further than the aFe Pro DRY S air filter. It will dramatically increase the airflow to your engine over the stock paper filter, with excellent filtration efficiency. And under normal driving conditions it will last twice as long as the stock filter. When service is required its easy, because oiling is not required.