Reinforced design for longer life and better efficiency. Traps impurities in the water. Wick filter fits Holmes HM1645, 1730, 1745, 1750, 2200, 2220 (HWF-64) (#B), Sunbeam SCM1746, 1747 (SF213), Touch Point S30E, S30E-A, White-Westinghouse WWHM1645, 1750ZE (WWH640, Hamilton Beach 05520, 05521 (05920), Bionaire BCM1745 (BWF-64).