How to choose multi-channel pneumatic-electric slip rings?

The second industrial revolution made us to the electrical age. The advancement of science and the development of science and technology have made us develop by leaps and bounds in the electrical field. Electrical automation equipment has been widely used in many fields, and electric slip ring as a common accessory in electrical automation equipment has also been developed faster and faster

As a common component in automation equipment, Electro Optical Slip Ring is more easily damaged due to its unique nature, so many manufacturers replace the Fiber Optic Rotary Joint by themselves, so how to choose the Pneumatic Rotary Union suitable for our own equipment?

First of all, please confirm the number of circuit and power and signal in the slip rings you need (usually one input and one output)

Secondly, how to install the pneumatic slip ring you need (we have through-hole installation, flange installation and through-hole flange installation

Thirdly,  specification of connectors, current 

Fourthly, The air inlet and outlet methods of the pneumatic slip ring.