Replacement filters for Fleetguard OptiAir Air Cleaners deliver superior performance and proven protection. • High-efficiency cellulose media is a proven performer across a wide range of heavy-duty diesel engine applications. • Unique sawtooth design compresses to cushion and hold the filter in place, providing a secure seal – even in severe environments. • RadialSeal™ design allows for fast filter changes. • Durable structural support protects filters from damage or collapse in heavy vibration applications or humid conditions.