The Glasfloss Z-Line Series pleated filters offer improved performance for virtually every application. All Glasfloss Z-Line pleated filters feature fibers which do not absorb moisture and will not support microbial growth. The Glasfloss Z-Line Series ZL filters achieve a MERV 8 rating.Specifications:Glasfloss Z-Line Series ZL air filters are of the extended-surface pleated-media type. The media utilized is made of 100% synthetic fibers. The media is pleated in a tapered radial configuration. A heavy duty, recycled expanded metal reinforcement is laminated to the air-exit side of the media by a thermo-setting adhesive to maintain continuity of the radial pleats. The expanded metal is galvanized to resist rust and corrosion. The pleated cartridge is bonded to the peripheral interior of the outer frame. A heavy-duty moisture-resistant beverage board incorporating post-consumer material is utilized for an encasing frame. The frame face is internally laminated to the pleated cartridge apexes. Glasfloss Z-Line Series ZL filters are classified under U.L. std. 900 and are rated to withstand temperatures up to 180 degrees Fahrenheit.