Maybe it is rated for a total of 15 Amps @ 5vdc total across all ports (which would be a really nice hub!). IF it shows the total power being consumed in real-time, that would be an awesome feature for some people.
The USB-A port is rated for 5vdc maximum and all USB-A devices are 5 volts. SO having a 15V hub would not make any sense.
It displays the voltage being used and power info, it says the total power is 15V
Power is measured in amps or watts.
Maybe it is rated for a total of 15 Amps @ 5vdc total across all ports (which would be a really nice hub!). IF it shows the total power being consumed in real-time, that would be an awesome feature for some people.
The USB-A port is rated for 5vdc maximum and all USB-A devices are 5 volts. SO having a 15V hub would not make any sense.
USB-C can do higher.