10Pcs/Set Aquarium Plant Tank CO2 Ceramic Diffuser Disc Carbon Dioxide Reactor Slice _x000D_ Description: _x000D_ Replacement CO2 diffuser disc, high-density with silicon sealing ring, does not easily block. Tow sizes available : Dia. 3cm/ 1.18" or Dia. 2cm/ 0.79"; Each Pack comes with 10 piece. Helps to ensure plants receive proper amounts of CO2, improve the growth and health of your plants with sufficient CO2 supply. The CO2 diffuser disc must be screwed as tight as possible when installation. Notice: The CO2 diffuser may release big CO2 bubbles during its first 1-3 days of usage. When ceramic disc becomes saturated with water, it will then release fine CO2 bubbles, this is normal and may take up to 3 days. _x000D_ Specification: _x000D_ Material: Ceramic _x000D_ L: Diameter: 3cm/1.18 inch _x000D_ S: Diameter: 2cm/0.79 inch _x000D_ Package Includes: _x000D_ 10 Piece Ceramic Disc _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_ _x000D_