A+C (ALV-USBACFS/SS) pairs one USB-A port with one USB-C port, 118W combined. C+C (ALV-USBCCFS/SS) pairs two USB-C ports, 120W combined, with one port supporting the full 20V/5A QuickCharge range. Ask the customer what they're charging - USB-A still suits older accessories, while most current phones and laptops are USB-C.