About this item Widely applicable: Suitable for hydroponic systems, ponds, aquarium fish tanks, helping extend the life of your nutrient solution, keep fish/ roots healthy and promote plant growth Air Stone Dimension: 2 "D x 2" H Recommended a high-output air pump at least 8W-10W or a commercial air pump Fits for 3/ 16 inch standard airline tubing Quality and safe materials: Made of safe and washable material(Soak them for at least 2 hours before use)