Our Glasfloss Z-Line Pleated Merv-8 4" Air filters offer the right combination of price and performance. saving your time and money along with protecting your HVAC equipemnt. These are commercial grade Air Filters and utilize Kimberly Clark media. We offer many Filter sizes for most any particular application including hard to find items. If you don't see what your looking for just ask.  These HVAC filters are rated at 3 months but may need to be changed more frequently based on environmental conditions. From pre-filters to primary Air filters for computer room units, laboratories, hospitals the Glasfloss Z-Line Series Pleated Filters offer a solution for virtually every commercial, industrial and residential HVAC application.