2 Pack Of EcoPlus 4 Inch Round Air Stones With 25 Of Airline Tubing By Aquarium Masters for Hydroponic Systems, Fresh Water Ponds, Aquariums, Aquaculture! 2 Pack Of EcoPlus 4 Inch Round Air Stone Discs With 25 Of Aquarium Masters Airline Tubing for Hydroponic Systems, Fresh Water Ponds, Aquariums, Aquaculture! EcoPlus Hydrovescent Air Discs are great for aerating or circulating nutrients in your tanks or reservoirs. These air discs incorporate suction cup feet to keep your air disc secured without fear of it moving around or flipping. The air disc has a built-in 3/8 inch 90 degree elbow fitting that insures the airline connects freely to your fitting and prevents the air line from kinking at the base of the fitting. Air discs are great for use with EcoPlus Pumps The micro-pore design of the air discs energizes your growing solution as it aerates and circulates your nutrients. It will extend the life of your nutrient solutions. Helps to keep your roots healthy and promotes exceptional growth. The Deluxe Air Stone Disc is great to put at the bottom of your reservoir for aeration The 25 foot long silicone tubing can be easily hidden and blend into your hydroponics system. Designed to fit all standard outlets, including air pumps, check valves, filtration system, air stones, air flow control levers Package contains two EcoPlus 6 Inch Air Stone Discs ( 728416 ). Consider these other items: hydroponics air pump, aquarium air pump, airline tubing, and check valves.