The Glasfloss Z Line Series Pleated Filters Offer Improved Performance For Virtually Every Application. All Glasfloss Z Line Pleated Filters Feature Yellow Fibers Which Do Not Absorb Moisture And Will Not Support Microbial Growth. The Pleated Cartridge Is Encapsulated and Bonded Into A Heavy-Duty Beverage-Board Frame To Ensure Filter Integrity In High-Moisture Applications. This Merv 11 Filter Provides High Performance with Low Pressure Drop for Energy Efficiency. The Glasfloss Z Line Series Filters Achieve A MERV 11 Rating. These Filters Are The Replacement For Honeywell, Air Bear, etc.