Nominal Size: 16" x 25" x 1".Actual Size: 15-3/4" x 24-3/4" x 7/8".3M Filtrete 2001DC Ultra Allergen Filters are sold in cases of six.The Filtrete Ultra Allergen Reduction Filter carries a 3M Microparticle Performance Rating (MPR) of 1250 - roughly equivalent to a MERV 11 rating.