The Pre-Filter Set (1911B5-2) is for use with the 80V max (40V max X2) XGT® 10 Gallon HEPA Vacuum Wet & Dry Vacuum with AWS® (GCV07 sold separately). The Pre Filter filters material collected by the vacuum. The 1911B5-2 features automatic filter cleaning, which is a layered design that shakes dust from the pre-filter during both compression and expansion which cycles when the dust extractor powers on and off. It features durable construction and is made from high quality materials for long life. It installs quickly and easily for added user convenience.