Description: Simple and lightweight, space saving. High quanlity aluminium inline CO2 atomiser with build in bubble counter and check valve function, all in one piece! Just plug this atomiser with your water pipe and CO2 tube to operate, recommended to use it with 4 - 5 mm inner diameter co2 tube Can dissolve CO2, but also through the flow of small CO2 bubbles into the every corner of the aquarium, so that aquarium plants can directly absorb free CO2. It is perfect for planted aquarium and coral reef tank Specification: Material: Aluminum Alloy + Glass Applicable Water Tube Inner Diameter: 12mm/16mm Applicable Co2 Tube: Inner Diameter: 4cm/1.57inch Ceremic Co2 Diffuser Inside Diameter: 2cm/0.79inch Package Includes: 1 Piece Inline Co2 Atomiser Diffuser 1 Piece Fixed Screw 1 Piece Fixed Rack Note: Since the size above is measured by hand, the size of the actual item could be slightly different from the the size above. Due to the lighting effects, monitor settings,etc.There could be some slight difference in the color tone of the pictures and the actual item.