The C39 outlet allows both C14 and C20 plugs to be connected to a singular outlet. Like its NEMA counterpart, the 5-20P, the C39 outlet allows for both 15 and 20-amp inlets. The flexibility of this universal outlet allows you to swap equipment without having the inconvenience of re-ordering a new rack PDU to meet specific outlet count requirements on a per-rack basis. Up till now, you would have been forced to make the determination ahead of time for the C13 outlet and C19 outlets required for your deployment. With the changing dynamics of IT applications, you could quickly outgrow your PDUs or require an outlet count change.