Heavy duty HEPA vac attaches to an ordinary 55-gallon open top drum to turn it into a powerful, industrial vacuum cleaner. The vac is designed to move more material with less wear. In addition, this vacuum has been engineered to filter contaminants to HEPA requirements in dusty environments requiring frequent cleaning. It is extremely quiet at 82 dBA (half the noise of electric vacs), making it suitable for a wide variety of environments.