Description: Increases oxygen and safe to your . Hemisphere shaped,easy to use and suitable for aquarium hydroponics. Long term use,such as dirt blocking,can be taken out for repeated use. With high temperature sintering,durable material,can be cleaned repeatedly. Create lots of small,tiny bubbles,suitable for aquarium, tank and circulation system. Specification: Material: Sand Color: Blue Size 10CM: Diameter:Approx.10cm / 3.94inches;Height:Approx. 7cm / 2.76inches;Interface Length:Approx.1cm/ 0.39inches;Interface Diameter:Approx.4mm / 0.16inches Size 12CM: Diameter:Approx.12cm / 4.72inches;Height:Approx. 7cm / 2.76inches;Interface Length:Approx.1cm/ 0.39inches;Interface Diameter:Approx.4mm / 0.16inches Usage: 1.Soak the product in water for 15 minutes before using. 2.Please use the windpipe (need to be purchased separately) to connect the bubble stone and the other end of the air pump (need to be purchased separately). Package Includes: 1 piece Air Stone Aerator. Note: Since the size above is measured by hand, the size of the actual item could be slightly different from the size above. Due to the lighting effects, monitor settings, etc. There could be some slight difference in the color of the pictures and the actual item.