FilterBuy Humidifier Wick Replacement Filter Compatible with Kaz WF1 & Emerson HDF-1. Designed to Replace Kaz Part # KO1 & Emerson Part # HDF1. FilterBuy replacement humidifier filter compatible with Kaz WF1 & Emerson HDF-1. Designed and engineered by FilterBuy to replace Kaz Part # KO1 & Emerson Part # HDF 1. Manufactured by FilterBuy to fit Kaz Humidifier humidifier models 885, 3000, 3300, and 3400. Also compatible with the following Emerson humidifier model #'s: HD1021, HD200, HD300, HD3000, HD400, & HD4000. Humidifier FilterBuy: Breathe Better!