Aquarium Air Stone "Bubble Bubba"micro-bubbler by Bubblemac Aeration Products. Healthy Eco-Systems Have The Proper Balance Of Oxygen And Nutrients To Sustain Plants, Fish and Other Living Organisms. Bubblemac has manufactured and distributed high-quality air diffusers and aeration products since January, 2000. {3.5 million air diffusers} Time tested in fish farms, college labs and public aquariums worldwide. Diffuser measures 1" x 1" x 3" with a 3/16" air line connection barb. {Suggested CFM=.30 or 7-10 lpm}, making this diffuser compatible with most low cost air pumps. SELF-WEIGHTED DESIGN. {You don't have to "weigh-it-down", it will stay put!}