Using 4-layer circuit board: it has very strong anti-interference , effectively ensuring the stability of PCI-E high-speed signal transmission, data integrity, impedance matching. PCIE interface expansion effectively solves the problem of insufficient PCI-E interface. This product can expand 4 PCI-E. Fast startup, high-speed loading and file transfer. Low power consumption, quiet, and durable. High gold plating: strong oxidation resistance, good conductivity and wear resistance. Product interface: m.2 key PCIe Number of interfaces: pci-ex1 interface * 4 System: OS / Windows / Linux Colour: black Material: PCB Size: 22x80mm Package Contents: 1 * Pci-E Expansion Card 1 * Screwdriver 1 * Screw Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.