For installations as a stand alone filter or to replace various other types of prefilters. Designed to withstand the demands of tough industrial and commercial applications. Uniform gradient density media with skin backing downstream tackifier. High dust holding capacity. Larger effective filtering surface area. Lower pressure drop. Heat sealed bond prevents air bypass. Increased filter integrity. Pliable for "hard to service" applications. Frame is composed of recycled material. Interlocking tab frame corners.