The air tube provides you with the convenient usage while setting up a pump. It allows you to connect one end of it to the powerhead's outlet and the other end to the airstone(if necessary).
The air tube also allows you to vacuum the dirt and the excess water out of the tank. While required, air tube can also help in other areas of work. For instance, creating a project or even, medical usage. Air tubes are flexible and depending on your creativity, you might be able to find it useful.
Diameter of the opening: 4mm
It comes in different lengths, ranging from 3 metres, 50 metres, 100 metres to 200 metres.