The VacuVortex Muffler Diffuser External HEPA Filter is designed to stop exhaust and improve indoor air quality. This filter, made of plastic and in black color, is compatible with wet/dry shop vacuums and is suitable for universal models. Manufactured in the United States, this unit includes one filter and is a must-have for those looking to enhance the efficiency of their vacuuming experience. Designed to stop the exhaust from blowing debris throughout your project but later found out it is a external HEPA filter. It filters out 99.80 of contaminants greater than 3 µm. It’s patented it’s not pretty, but it works.