TWINSTAR CO2 DiffuserThe Twinstar CO2 Diffuser has the lowest hole size among aquarium diffusers. With a mesh size of 15. 3um, the micro bubbles generated can quickly and effectively raise the appropriate concentration in the aquarium with lower amount of carbon dioxide supply. Made by hand, these diffusers has gone through 10 processes to achieve the best quality and final product to live up to the established Twinstar quality. With sand brown stone and acrylic design