Features: Aquarium Air Stone Suction Cup,NanoBubble Stone,Oxygen Diffuser,Diffuser Air Stone,Fish Tank Bubblers Pump,Oxygen Stone low-pressure atomization，Fine Bubble: Produces steady-stream of tiny bubble and increase oxygen rate in water. Micro-bubble burst quietly on the water-surface. The size of bubble can be adjusted, the air ,evenly released, and bubble are delicate Quiet design, high dissolved oxygen rate in water，Double suction cup fixed, not easy to fall off.Good for shrimp, fish, and all kinds of aquarium creature. Note: soak in water for 10-20 minutes before use, and the effect is best after installation. When installing the suction cup, it is best to wet the suction cup with water, or install it in water. The glass tube is small and easily broken. Please install carefully. Specifications: Material:acrylic, gravel Size:s/=m/=l s-5x10cm/1.97x3.94in,m= 7.2x6.8cm/2.83x2.68in,l-11x7cm/4.33x2.76in Color:white/blue/red Package Includes: 1xAquarium Air Stone Suction Cup note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color of the item.