VTM401 V-TUF bags provide an extra layer of HEPA filtration, ensuring the V-TUF STACKVAC vacuum becomes fully compliant with all M-Class silica dust regulations. The V-TUF STACKVAC dust extraction vacuum bags (Order Code: VTVM401) must always be used when operating the machine, to ensure full protection from hazardous dusts escaping back into the air and harming the lungs of the surrounding workforce.