Accumulair 12x24x5 (11.75x23.75x4.38) Carbon Odor Block Aftermarket Honeywell Replacement Filter Nominal size 12x24x5 actual size 11.75X23.75X4.38 Carbon impregnated disposable pleated panel filters A simple solution for controlling both odors and dust particles Lasts up to 6 months This filter is made by Accumulair