1. Does 4K ultra HDMI cable support the expansion mode? Only copy mode is supported, and extended mode is not supported. 2. What is the actual display of the display device with different resolutions at the same time? Display devices with different resolutions are backward compatible with the lowest resolution. If the display devices connected to 1080P and 4K are displayed at the same time, they are 1080P. 3. What is the supported formats? Ultra hdmi cable outputs dual-channel 1080P video stream, support universal 3D format. 4. Why does the picture quality is not clear after connecting the HDMI cable? Check if the device supports 4K HD resolution. In addition, 4K ultra HDMI cable within 3m and 3m support HDMI2.0. 5. Which devices are supported by the HDMI cable? Devices with standard HDMI interface can be used. Support audio to amplifier, laptop to projector, etc. 6. Can 4K ultra HDMI cable support audio and video synchronization output? Yes, support HDMI for simultaneous transmission of audio and video signals. In the case when TV cannot make sounds after being connected, check if the audio output setting is selected as HDMI OUT. 7. Is the gold-plated joints better than nickel-plated joints? Yes, it has the better performance in anti-rust, anti-oxidation, plugging, and durable use. 8. Is there a certification of HDMI association? Yes.