Falcon Carbon FilterFalcon Filters contain 100% Australian Rc 4 8 active carbon, exclusively extracted from the mines of Collie Basin in Western Australia. This is the oldest, purest, and lightest carbon in existence, and it is the top tier of carbon from Collie, used exclusively in this filter. Falcon Carbon Filter 125 300 mm 500 m h Maximum flow (m h): 500 Mouth Diameter (mm): 125 Length (mm): 300 Weight (kg): 2. 62 Falcon Carbon Filter 150 300 mm 600 m h Maximum flow