You need to use the HDMI USB cable that comes with in the HDMI box to connect any USB-A port or any USB-A adapter. It is necessary to connect the HDMI USB cable since some HDMI slots (most cameras such as GoPro 7 Black) cannot provide enough power for the fiber optic HDMI cable at some time. The HDMI fiber optic cable is an active cable, it needs enough power to work properly. If the power is insufficient, there will be a black screen, screen flicker, no signal and other problems. Compatible with Raspberry Pi 4, GoPro Hero 7 Black, Hero 6 Hero5, Hero 4 Silver, Hero 3 White, Hero3+, Go Pro Hero 2018, Sony A5000 handycam, Sony A6500 A6000 A6400 A73 A7S camera, Nikon b500, Canon EOS M50, IdeaPad Miix 300 Tablet, Ideatab Miix 700 Miix 2 710 S6000, ThinkPad 10 8, Yoga 2 Pro 3 ultrabook, Yoga 700 710, 710s, ASUS ZenBook UX305UA, Transformer Mini T102HA. Support 3D, HDR, UHD, HDCP, Audio Return Channel, HDMI Ethernet Channel, Compatible with Dolby TrueHD, and DTS-HD Master Audio. This 50 Feet 16 Meter fiber optic cable supports 4K 60Hz, 2K 60Hz, 1080p 60Hz with life-like color. Micro-HDMI to HDMI cable, directional fiber optic cable, connects Micro HDMI device to HDMI device. Please check your device and make sure source device is Micro HDMI port, and display device is standard HDMI port.