The Donaldson P778399 is a high-efficiency primary air filter featuring Radialseal technology and cellulose media, designed to provide superior engine protection. With an outer diameter of 248 mm and a length of 350.5 mm, this filter ensures 99.9% filtration efficiency, crucial for maintaining optimal performance in demanding agricultural and construction machinery. It is a direct equivalent for various OEM part numbers, ensuring broad compatibility across brands like AGCO, Caterpillar, Claas, John Deere, Massey Ferguson, New Holland, and Valtra.