Air Filter, Primary Radialseal, Donaldson P532501 Equivalent: CAT 6I-2501, CAT 128-2686, Available FREE Shipping on orders over $2000 Login for price Description Technical Information:Outer Diameter: 281.6 mm (11.09 inch)Inner Diameter: 147.9 mm (5.82 inch)Length: 327.2 mm (12.88 inch)Efficiency: 99.9 %Efficiency Test Std: ISO 5011Type: PrimaryStyle: RadialsealBrand: RadialSeal™Media Type: CelluloseCross Reference:Atlas Copco: 9772040085Caterpillar: 128-2686, 6I-2501Application:Caterpillar: 3126B, 3306C, 3306B