A "USB extension 3.0" is a cable that extends the reach of a USB 3.0 connection, typically used to connect USB 3.0 devices to a computer or hub at a distance greater than the standard USB cable length allows.

The product you're describing is likely an 8-in-1 USB Type-C to HDMI adapter or cable, packaged in a black and yellow box. It's designed to connect devices with a USB Type-C port (such as laptops, smartphones, or tablets) to an HDTV or monitor with an HDMI input. This type of adapter usually offers multiple ports in addition to HDMI, such as USB-A, USB-C, Ethernet, SD card slots, and more, providing users with versatile connectivity options.