True Blue 24x240x1 30 Days' MERV 2 Hammock Air Filter. It is effective against dust, lint, mold spores, bacteria, pollen, and smoke. This frameless filter is on a roll and can be cut to size. The Flanders hammock roll is made of continuous filament spun glass media and is available in the standard depths of 1 inch or 2 inch. Its glass fibers do not promote the growth of microbial bacteria. This filter is available in a length of 20 feet and in various widths. Hammock rolls are easily cut with scissors or a utility knife to fit any size furnace. The hammock roll is packaged in a sturdy carton that doubles as a convenient dispenser.