Enlightened Flexible Fish Tank Submarine Air Curtain Bubble Tube Durable Oxygen Bubble Tube for Aquarium Product Description: Item Type: Bubble Tube Material:Rubber Color:Black Feature:Durable Occasion:Fish Tank Length(S):20 cm/7.87" Length(M):30 cm/11.81" Length(L):45 cm/17.72" Length(XL):60 cm/23.62" Length(XXL):70 cm/27.53" Size(head,outer diameter*inner diameter):0.35*0.27 cm/0.14"*0.11" Size(tube,outer diameter*inner diameter):1.2*1.0 cm/0.47"*0.39" Package Include: 1 x Bubble Tube Notes: 1. Please allow 1-3 cm difference due to manual measurement and 3-5 g for the difference between different colors. 2. Due to the screen difference, the color may be a little difference from what you expect, please allow it. 1. Material: the rubber is durable and non-toxic, and it will not rotten and pollute the water. 2. More Choices: there are five sizes for option, and you can choose the suitable one according to the demands. 3. Equally: the bubble can disperse equally and make a beautiful bubble curtain to make your fish happy and your fish tank is attractive. 4. Easy to Use: it must match with the air pump, and you just need link it with air pump and put it on the bottom of fish tank. 5. Convenient: you can make the hose into any shapes according to your fish tank because the tube is soft enough.