15 3/4 x 24 1/4 x 3 inches. Merv 11 (3-pack) 15 3/4 x 24 1/4 x 3 inches Exact Sizes. REPLACE LENNOX XO581 or any filter with the exact same size, 15 3/4 x 24 1/4 x 3 inches. MERV 11 Each Box Contains 3 Filters. MSRP: Was: $150.00 Now: $135.00 Add to Cart