What's the name of the air connection of the air pump?

What's the name of the air connection of the air pump? The joints required for air pump to blow water are terminal metal pipe joints such as tee joint and four-way joint. Because the diameter specifications of the air pump and the pipeline are different, it needs to be connected by reducing pipes, which requires pipe joints with many openings, and the pressure of blowing water is relatively high, so it is necessary to use terminal metal pipe joints, that is, terminal metal pipe joints such as tee joints and cross joints.