Dymax CO2 Glass Atomiser GA105 is made of glass and features a high quality ceramic disc to provide optimum diffusion of CO2. It is durable and compact in size and thus easily installed. It should be placed at the bottom of the tank in order to obtain the optimum result. When the ceramic disc is blocked, simply soak it in bleach water for 3~5 minutes then rinse with tap water and reuse again.