The DR-E6C is designed for use with the EOS R5 C and is required for the camera to operate when in "Video" mode+. The coupler connects to external power supplies, such as the CA-946 Compact AC adapter, to deliver power directly to the camera without a battery.+ Please note that the DC Coupler DR-E6 will only supply power to the EOS R5 C when in "Photo" mode.