Two carbon filters - round shape Dimensions Diameter: approx. 109mm Height: approx. 25mmCompatible with SNDOAS Wall Mount Model GD1775BPA,GD1790BPA, GD2475B and GD2475BPBEasy installation, no tools requiredWe recommend that you replace carbon filter every 3 months.Contact us before buying if you are not sure.Quantity: Pack of 2 Product Description Thank you for choosing our Carbon Filters for range hood Series GD17, GD24 Quantity: Pack of 2 Measures: Diameter: Outer 109 (mm) , Height: 24 (mm) Suggest changing to new one every 3 months (According to different kitchen condition, the life time of carbon filter might be longer or shorter than 3 months). Installation: Fix carbon filter into the unit and turn it in clockwise direction. Repeat the same on the other side. Important Notice: 1.Make sure the filter is securely locked. Otherwise, it would loosen and cause abnormal noise and danger. 2.Using carbon filter would reduce the air flow of the range hood.