The Aprilaire 216 whole-house filter is labeled “20x25x4 (same cabinet as 210/213)” but actually measures 20.2 x 25.4 x 3.77 inches. Unlike 1″ filters, 4″/5″/6″ whole-house filters don't share one universal nominal-to-actual conversion — always match by brand and model, not just the printed size.
MERV 16 upgrade filter for the same cabinets as the 210/213 (1210, 1620, 2210, 2216, 3210, 4200) — for buyers who want the highest filtration that cabinet supports. This is from the manufacturer's own spec sheet.
Match by brand + model, not nominal size. Confirm against your old filter or equipment manual before ordering.
Looking for a 1″ furnace filter instead? Use the full FilterKey tool.