Hydroponics Reservoir / Water Culture System - Air Diffuser / Bubble Stone / Air Stone / Aerator, by the manufacturers of "The Forever Bubble Stone" and Bubblemac Aeration Products, High-Quality, 100% Glass-Bonded Silica Air Diffusers. {Self-Weighted} Perfect For Hydroponics Reservoirs and Water Culture Systems, Manufactured from 100% Glass-Bonded Silica this Air diffuser has been the "Industry Standard" in Fish Farms and Hatcheries Worldwide for 35 Years. Bubblemac Air Diffusers Provide The Highest Oxygen Transfer Efficiency. Rated Much Higher Than The Chinese Import Air Stones. Non-Clogging. Compatible With Most Low Cost Blowers {.35 CFM or 9-10 lpm}, These Diffusers Produce a Uniform Medium Fine Bubble. Diffuser Measures 1 1/2" x 1 1/2" x 3" and has a 3/16" poly barb {standard air line connection} RELIABLE, DURABLE AND DEPENDABLE describes "The Forever Bubble Stone" now available on Amazon in an application designed especially for Hydroponics / Aquaponics Applications. "IF YOU HAVE TRIED THE CHEAP IMPORTS .... DO YOURSELF A FAVOR AND TRY THE HIGHEST QUALITY AIR DIFFUSER ON THE MARKET TODAY !!" "Ya'll Got Bubbles"? - SPECS: 100% Glass-Bonded Silica, Maximum Pore Size 140 Microns, Nominal Partical Retention 50 Microns, Flexural Strength 2500 PSI, Bubble Size 1-3 MM, UNLIMITED LIFETIME When Used in pH of 8.0 or Less!