Honeywell model FC40R air filter # FC40R1037. Replaces Expandapac filter # FC35A1076 that was used in model F35R1036. Accumulair grill filter. Nominal size is 12 x 24 x 5. Actual size is 11 3/4 x 23 3/4 x 4 3/8. It has 98% efficient filtration media. High-efficiency filter media collects small dust particles before they can collect on your coils. No assembly required. no combs needed. filter just slides right in! Each filter is individually bagged. Use the bag to dispose of the old filter! Allow a 7 depth behind grille to provide space for the deeper filter and air flow through filter. Package contains 2 filters.