PREFILTER, FILTER TYPE PREFILTER, PERFORMANCE RATING UNRATED, ACTUAL DEPTH 3/16 IN, ACTUAL HEIGHT 17 13/16 IN, ACTUAL WIDTH 13 3/8 IN, COMPATIBLE GRAINGER PART NUMBER 2HPB1, 2HPB2, COMPATIBLE MANUFACTURER MODEL NUMBER 2HPB1, 2HPB2, NUMBER OF FILTERS 1, MEDIA MATERIAL SPONGE, NOMINAL DEPTH 17 7/8 IN., NOMINAL HEIGHT 5/16 IN., NOMINAL WIDTH 13 7/16 IN., FILTERS DOWN TO 5 MICRON, FILTERS OUT DANDER, DUST, FILTER EFFICIENCY NOT RATED, FRAME MATERIAL