AIR FILTER, PRIMARY RADIALSEAL DONALDSON BLUE. DONALDSON BLUE, OFF-HIGHWAY APPLICATIONS Why Choose Donaldson Blue Filters? Donaldson Blue lube filters are designed specifically for extended maintenance programs. • Proven Synteq – media delivers greater efficiency and higher contaminant holding capacity. • Removes more than 90% of contaminants 10 microns or larger (cellulose filters typically remove 50% or less). • Twice the contaminant holding capacity of standard cellulose filters – for longer filter life. • Direct replacements to standard filters – no system modifications. Product Brochure: