Glass Air Stones - 4 Pack

These glass air stones are made of tiny vitreous spheres which are fused together as a porous unit. This produces uniform bubbles of precise size for maximum aeration. Preferred by many aquarists over plastic and sand type air stones. They are an excellent aeration device for use in under gravel filters, corner filters or just as decorations. For use only with standard airline tubing (sold separately). For use in freshwater or marine aquariums. Each diffuser is approximately 1-3/4" long by 1/2" diameter, excluding the 3/4" clear stem. 4 diffusers per package.