Shop Vac Users: If you are looking for a replacement for Shop Vac Cartridge Filter, Part # 90304, then this filter may work for you! Some Shop Vac models have a fitted filter slot around the filter cage, if your vacuum has this then our filter will not fit, otherwise our filter will fit your vacuum. Please contact us if you need any help, we would be happy to let you know if our filter will fit your vacuum. This does not come with the locking cap needed to secure onto the filter cage, but will work with your previous cap. Please contact us if you have any questions, comments, or concerns. These filters are manufactured by Kopach Filter LLC and it is not a product of, or sponsored or endorsed by Shop Vac®.