Our Nano disc air stone is made of high-quality white alundum & brown alumina, fired at a high temperature of 1300 degrees Celsius.<br>The air diffuser area is very smooth and exquisite, not like other poor quality air stone touch rough.<br><br><b>This kind of air bubble stone has the following features:</b><br>· Super sturdy & durable, service life can be 2 to 3 years.<br>· Weighs enough to sink in the bottom, no need suction cups.<br>· Dissolve more oxygen to the water.<br>· Nice high output of amounts of bubbles.<br>· Produce quiet smooth dense small bubbles in the water.<br>· Strong filtration, for fresh and salt water.<br>· White color and disc shape, a good decor for your aquarium.<br>· Easy to clean.<br>· Comes with other accessories.<br><br>Want to create beautiful and fairy bubbles wall in your aquarium, please buy 2 or more different size of air stones.<br><br><b>Specification:</b><br>2 sizes: 2 inch, 4 inch.<br>Weight: the 2 inch air stone weighs 5.2oz/150g, the 4 inch air stone weighs 15.2oz/430g.<br>Outlet size：2 inch disc air stone can only be compatible with 4mm airline, the 4 inch disc air stone can be compatible with airline of 4mm or 8mm.<br><b>Compatible air pump wattage: the 2 inch air stone can be drove by 2W or larger wattage air pump, the 4 inch air stone can be drove by 4W or larger wattage air pump.</b><br><br><b>Warm Tips:</b><br>1. If have tubing frustration, soak the tube for several minutes before connecting it to air stone.<br>2. To achieve better effect, please immerse the air stone in water for an hour before puting it into use.<br>3. When the water depth exceeds 1.3ft (40cm), you may need an air pump with higher power wattage. <br>4. Cleaning tips: we suggest to clean the disc once a month, of course you can clean it more often. You need to clean algae and other impurities on the disc to prevent holes blocked.