Uxcell 2-Piece Ball Shape Aquarium Bubble Air Stone, 50mm, Blue Color: Blue; Material: Mineral, Plastic; Net Weight: 199g; Product Name: Aquarium Bubbles Airstone Connector Diameter: 2.5mm/ 1"; Air Stone Diameter: 50mm/ 2"; Model: NAR-024 Made of mineral material, it effectively create water currents and dazzling underwater scenes. Creates bubbles in fish tank while attached to an air pump(Not Included). An ideal tool to add oxygen to your hydroponic growing system