Air filters play a huge role in maximizing engine efficiency and fuel economy. Continual research and development has led to a range of features designed to optimize vehicle performance. Features include: Polyurethane sealing to withstand high temperatures and resist shrinkage and deformation Expanded outer screen cages to ensure maximum support and rigidity Variety of filtering media to suit a wide variety of conditions including highly variable temperature and humidity Oil Filters Oil filters prolong engine life by trapping dirt and other particles throughout your vehicle's service interval, ensuring only clean, filtered oil circulates around the motor. Features include: Anti drain-back valve preventing oil draining back out of the filter through the inlet holes By-pass valve ensures protection of the engine against oil starvation Strong internal components such as springs and element assemblies Heat tolerant seals and O-rings Kit Contains: WA5023 Air Filter x 1 WZ418 Oil Filter x 1 WCF31NM Fuel Filter x 1 WACF0040 Cabin Filter x 1