Here are the details for a USB 3.0 4-port hub with a cable length of 30cm: **Features:** - Adds four additional USB 3.0 ports to your computer or laptop. - Supports SuperSpeed data transfer rates up to 5Gbps. - Backward compatible with USB 2.0 and USB 1.1 devices. - Plug-and-play functionality; no additional drivers required. - Compact and portable design for easy transportation. - LED indicator to show power and activity status. - Over-current protection to safeguard connected devices. **Specifications:** - Ports: 4 x USB 3.0 ports - Transfer Rate: Up to 5Gbps (USB 3.0) - Cable Length: 30cm - Compatibility: Windows, macOS, Linux - Power: Bus-powered (no external power adapter required) - Material: Durable ABS plastic - Dimensions: Compact and portable design This USB 3.0 4-port hub offers convenient expansion of USB connectivity with high-speed data transfer rates and a compact form factor suitable for various devices and operating systems.

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.