A replacement Ceramic Cartridge. The cartridge is packed with Porous Ceramic granules and forms the very important Biological part of the filtration process. The Ceramic Cartridge can be rinsed out in a little aquarium water for a few months but the ceramic granules eventually become clogged and the cartridge should be replaced perhaps every six months.
The 102c carbon Cartridge is also used in the AquaNano range of aquariums, AquaVis 130 aquariums , Betta Duo and the Betta Trio aquariums, Xpression & AquaNano 25 aquariums.
Image is for illustration purposes only.