ATRACYPART air filters provide up to 99% filtration efficiency for dangerous particles, which keeps the engine free from particles and ensures optimal airflow into the engine for optimal engine performance. Package Includes: 2 Pack * RS3534 air filter Compatible with? Peterbilt 388 (2008-2015) Peterbilt 372 (1989-1993) Peterbilt 377 (1988-2001) Peterbilt 362 (1988-2004) Peterbilt 378 (1988-1999) Peterbilt 379 (1987-2007) Peterbilt 387 (1981, 2000-2011) Kenworth W900 (1981-2018) Kenworth T2000 (1997-1999) Western Star 4900FA (2002-2017) Western Star 4900E (1997-2002) Western Star 4900SA (2002-2017) Western Star 4900 (1987-2002) Western Star 4900EX (2002-2017, 2019-2020) Compatible Engines: Caterpillar 3406, C10, C11, C12, C13, C15, C16, C9, Detroit Diesel Series 60 Replacement OE Numbers: Baldwin RS3534 AF25248 Luberfiner LAF3302 Fram CA8231 Napa 6863 TR518 At ATRACYPART, we take pride in the quality of our products and in your satisfaction. If you have any problems, do not hesitate to contact us.