Standard 2 x 40mm Computer Dust Filter Overall size: 60mm x 131mm. Actual filter size: 40mm x 110mm. To fit all standard vents of this size or smaller. If the area where the filter needs to fit is made of a non-ferrous material, such as aluminium or acrylic, please select the non-ferrous button above. For more illustrations of this filter, click on the specs tab.