Estone 1pc Spiro V Glass Reactor Carbon Dioxide Co2 Ceramic Disc Diffuser Aquarium Plant Tank New Only sold by Heroneo.Photo taken by Heroneo. 100% Brand new and high quality Made of Glass. 5 Spiro in the diffuser. Atomic pores on the ceramic disc breaks down Carbon dioxide into tiny streams of bubbles. With high surface area per volume ratio. Suitable for 4mm inner diameter tubing.