Can be easily driven even by small air pumps, suitable for aquarium, and fish tank. MODEL: ASR-020. Jetting Volume: 1L/min, Recommended Air Pump Power: 2W-4W. Made of high quality non-toxic mineral material. Fits for 3/16" / 4 mm inner diameter tubing. Compact Diameter Size: 0.8"/20mm. Color: Grey. Net Weight: 4 oz/120 g. Soak the stone completely in water about 1 hour before use. Comes with 10 Pcs Ball air stones. Air Stone Spherical An airstone, whose purpose is to gradually diffuse air into the tank and provide oxygen for fish to breathe, is an necessity to have around your house if your are a lover of aquatic animals. Pawfly air stones are made of high quality non-toxic mineral material. With high temperature sintering, the stones are sturdy and durable, have high dissolved oxygen rate and create even and tiny bubbles rather than a limited number of large ones. Made of high quality and harmless mineral material Create tiny bubbles rather than bigger ones Keep providing oxygen for