Features: brand new and high quality The chassis expansion card from 19pin to USB3.0 accelerates the upgrade of the new formula simple installation of high speed and stability. Accelerate the upgrade of the new formula USB3.0 high-speed transmission enjoy the world fast, improve transmission speed (must be powered to use). Two-port expansion to for play external devices, keyboard, mouse, printer, cooling fan and other external devices, no matter how many, you can also for play at the same for time, no connection problems. The gold-plated thickened finger has good oxidation resistance, corrosion resistance, wear resistance, and stability. Ensuring good contact can effectively reduce packet loss and improve data transmission speed. Solid state capacitor adopts safe and stable solid state capacitor to reduce ESR, with excellent conductivity, no sudden heating and long service life. The large 4-pin port is fully powered and the four ports are fully charged, so the expansion interfaces do not affect each other and can meet the usb3.0 power supply standard. Multi-system compatibility: Powerful compatibility, not only for windows, vista, Linux and other systems, but also for MacOS 10.8.2 and higher, realizing the recreation of for Apple's "garbage can" and other devices. Specifications: Material: metal Color: black Size: approx. 120x73x72mm/4.72x2.87x2.83in Package Includes: 1PC x PCI-E Expansion Card note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!