AQUAPONICS {AS30L} - Air Diffuser Stones - 12" for FISH TANKS, 3 pack}, manufactured by Bubblemac Industries, Inc. makers of"The Forever Bubble Stone" Made Locally. Used Globally. THIS LISTING IS FOR A THREE PACK OF THE DIFFUSERS SHOWN ABOVE!!! Bubblemac Industries, Inc. has manufactured some 3.5 million of the highest quality "INDUSTRY STANDARD" air diffusers over the last 15 years. Our products are commonly found in use at fish farms across the globe, as well as in University and Lab settings. With Aquaponics becoming such a popular method of farming, we decided to make our 12" air diffusers available to the back-yard enthusiast. Specs for each diffuser model #00122 {AS30L}: 3/8" O.D. barbed fitting for connection to 3/8" I.D. air line - Dimensions are 1.5" x 1.5" x 12" - Machined of high-quality 100% Glass-Bonded Silica materials - Creates a uniform, Medium-Pore bubble sized between 1-3 mm - Maximum pore size of 140 microns - **{Suggested 1.0CFM or 28 lpm per diffuser}** Bubblemac Industries, Inc. - An American Made Company - These Bubblemac Air Diffuser Designs are used exclusively by Ryan Chatterson, Aquaponic Farm in Clermont, Florida.