* Fine Bubbles: The air stone produces lots of dense fine bubbles; A great way to oxygenate your hydroponic growing systems, ponds, aquariums and enliven the aquatic life * Size: 4" x 2" x 2"; Recommended air pump powe: 4 - 8 W; Standard ID airline tubing: 0.16" / 4 mm * Durable Material: Made of mineral material and sintered at a high temperature; The material is sturdy and durable which is safe to your fish * Easy to Use: Soak the stone completely in water for 2 hour before use; Clean it regularly with a brush as they get clogged after weeks or months of usage * Widely Applicable: Fit for hydroponic systems, ponds, aquariums or fish tanks and other systems *