The Glasfloss Z-Line Series pleated filters offer improved performance for virtually every application. The structure of the media fibers sustains efficiency over the service life of the filter and produces high dust-holding capacity. All Glasfloss Z-Line pleated filters feature fibers which do not absorb moisture and will not support microbial growth. The Glasfloss Z-Line Series MR-11 filters achieve a MERV 11 per the ANSI/ASHRAE 52.2-2007 Test Standard.