Filter-Monster branded replacement compatible with Austin Air Pet Machine (FR410) filter. Fits Austin Air models HM410, HM402, HM405, HM400, HM450. Package contains (1) filter, two (2) pre-filters. Approximate Dimensions - Diameter: 13.5", Inner Diamter: 7.25", Height: 14.5". Filter-Monster branded replacement filter compatible with Austin Air Pet Machine FR410 Air Purifier filter. Package contains one (1) filter and two (2) carbon pre-filters. Engineered to fit Austin Air Pet Machine (HM410) Air Purifier. Also fits Austin Air models HM402, HM405, HM400, HM450.