Can-Filters has over 15 years experience specializing in activated carbon odor control and uses only Virgin Activated Carbon. The CKV-4 (carbon type) is specially developed for this purpose. Controlled grain size and a large surface area give full rated airflow and more than 99% odor removal. Carbon bed thickness is 2.5" - More carbon means more absorption! Can-Filters packed bed design means no settling and no preferential channels for consistent performance and long life.