24x28x2 MERV 11 GeoPure Geothermal Air Filter (pack of 4) Nominal Size: 24x28x2 Actual Size: 23-1/2 x 27-1/2 x 1-3/4 MERV 11 - Heavy Duty Industrial Construction High Capacity - Extended Life Premium filter designed for an exact fit in Climatemaster and Carrier Geothermal Heat Pumps