This 5.25-inch panel converts the motherboard USB 19-pin and 9-pin interfaces into 2 USB 3.0 ports and 2 USB 2.0 ports. It can be installed in an idle optical drive bay to provide front USB access, so you no longer need to reach behind the PC. Key features - Front USB hub: adds 2 USB 3.0 ports and 2 USB 2.0 ports from the motherboard header. - Front-panel convenience: installs in a standard 5.25" optical drive bay for easy access. - Simple installation: designed to sit in the optical drive position of the chassis. Important notes - If the panel is connected to USB 2.0, USB 3.0 devices will not operate at USB 3.0 speeds. - Compatibility: before purchasing, check the chassis optical drive bay mounting holes. If they are elongated, ensure there is enough space; if they are round, verify the diameter to avoid misalignment and uneven installation. - Audio signal path: audio is routed directly from the motherboard; sound quality depends on the motherboard and the playback device. The panel cable does not change sound quality. Use scenarios - Upgrading a case with limited front ports: gain front access to 2 USB 3.0 and 2 USB 2.0 ports for drives, peripherals, and dongles. - Home theater PC or compact PC: convenient front USB access for keyboards, mice, USB drives, and streaming dongles. - Desktop maintenance or data transfer: quickly connect USB devices without reaching behind the PC chassis.