HEPA filter for purifier Q34F and other similar purifiers. It consists of 3 layers: a photocatalytic titanium filter layer, a high-efficiency HEPA non-woven layer, and activated carbon. The first layer of the filter captures dust and hair in the air. The HEPA filter removes airborne dust particles PM 2.5 and smoke. The honeycomb-structured carbon filter absorbs and decomposes formaldehyde, phenol, smoke, and mold. dimensions: 34x28.5x2.5cm Number of pieces in carton: 50