Description This professional Air Stone is made of high-class materials, durable and practical, and has a long service life. This is a great way to add oxygen to your aquarium, fish tank, hydroponics and circulatory system. Very suitable for use in fish tanks and aquariums. It will be your good choice. Features -Color:Blue-Material:Sand, plastic- Size: 4.00X1.50X1.50cm/1.57X0.59X0.59in-Note:Suitable for hose with inner diameter of 4mm.-Durable, very suitable for home, office fish tanks, aquariums and hydroponic nutrient tanks.-The surface is fine and smooth, and the bubble output is more uniform. The installation method is simple and easy to use, save your effort.-Air Stonecan be used for aquarium purification, filtration, water quality and oxygen aeration.-It can be washed repeatedly and undoubtedly can be used for a long time. A practical and useful tool for your fish tank, help to create more air bubbles.-This air stone can produce tiny bubbles, increase oxygen content and circulate nutrients.Packing list: 25 x air stones