Pollen Glass is a CO2 distributor, which virtually pollinates the entire aquarium with tiny carbon dioxide bubbles. Pollen Glass is hand made from high quality Japanese glass. Its form is designed for use in a standard size 60cm aquarium (approx 20 Gallon) or under.

30MM specifications: Use on tanks ~90 cm (~200 Litre)
40MM specifications: Use on tanks 90cm ~ 120cm Tank (200-300 Litre)
50MM specifications: Use on tanks larger than 120cm Tank (Beyond 300Ltr)