This charcoal filter is specially made for use in Samsung microwaves. It is 6 inches long and 4 inches wide. It is responsible for absorbing the fumes and odors produced during the microwaving process. It captures these odors and prevents them from lingering inside the microwave and in your kitchen. The filter is made of activated carbon, and it can be found over or behind the microwave vent. Over time, it is normal for the filter to become saturated with food particles and odors which prevents it from carrying out its function effectively. If you notice an unpleasant smell inside your microwave despite cleaning or see visible build-up or damage on the filter, then it is likely time to replace the filter.