Micro-Air P1455 95% DOP HEPA filter replacement with FSC certified CARB compliant MDF frame. Guaranteed fit and performance. ISO E11 rated. Replacement Filter for Micro-Air P1455 95% DOP HEPA Filter, ISO E11 Rated FSC Certified CARB Compliant MDF Frame 23.3 x 23.3 x 11.5 Inches Exact 100% Guaranteed Fit and Performance Fits models MX3510, OM3510, MA421 Filtra-Systems Micro-Cell HEPA filters filters are designed to meet critical filtration requirements in the most sensitive applications. Micro-Cell HEPA filters are constructed using ultrafine wet-laid microglass filter media and corrugated aluminum pleat separators. Micro-Cell HEPA filters are recommended for use in medical facilities, pharmaceutical mfg., food processing, microelectronics mfg., and nuclear or biological applications. *NOTE: Brand names are used for identification purposes only, and are the intellectual property of the OEM. Filters are OEM Replacements manufactured by Filtra-Systems and are not OEM Brand products unless specifically stated as such. Filtra Supply is not related to the OEM.