The self-supported 4” Micro Shield™ Mini-Pleat Filter utilizes a geometrically formed pleat pack. Each pleat pack is further strengthened with rigid, mechanical pleat separators. The pack is then sealed into an all-plastic frame. Each stage of the assembly process is quality-controlled to ensure the filter’s performance, consistency, and durability. These design and construction features combine to produce the best all-around performance in airflow, efficiency, and dust-loading uniformity.