Filters odor. Used in ducted and non-ducted range hoods, microwaves, bathroom fans, and other applications requiring odor removal. Typically used in conjunction with an aluminum grease filter when installed in range hoods. Carbon Fiber filters can not be washed, and have a usefull life of 6-12 months. Constructed of charcoal impregnated polyester media sandwiched between 2 layers of galvanized expanded steel.