Each cable has two ends, the power source end, and the device end.
All iPhone version 15 and 16 phones are charged using a USB-C connection at the device end of the cable.
The choice of the which connector is on the power source end depends on your wall plug, laptop or power bank.
The most common choice is a USB-A to USB-C cable. However, if your power source has the newer rounded USB-C socket, then a USB-C to USB-C cable is what you will need.
The gomi power bank has both a USB-A and a USB-C port, and so both of the USB-A to USB-C cable and USB-C to USB-C cable options are suitable
Most common cable ports and connectors:

This advice applies to :
- iPhone 15
- iPhone 15 Plus
- iPhone 15 Pro
- iPhone 15 Pro Max
- iPhone 16
- iPhone 16 Plus
- iPhone 16 Pro
- iPhone 16 Pro Max
- iPhone 16e