Nominal: 16 x 20 x 4-1/4, size: 15 1/2"x19-7/8"x4-1/4" 16x20x4 1/4, ac furnace air filter comparable to filtrete mpr 1500 and 1550 ultra allergen defense replaces bryant/carrier part numbers: filccfnc0017, filbbfnc0017 replaces lennox part number: x0582 change frequency 12 months. made in the usa
