Why are wire leads used instead of screws on the GUAC1 and GUAC2 GFCI USB devices? May 16, 2024 15:17 Updated Follow It allows for the highest possible power to be provided, as well as helps manage the heat generated by the devices. Related articles Can the same neutral wire be used for the installation of more than one Dual Function AFCI/GFCI Receptacle? How do I know where the first outlet in the branch circuit is?