Using 4-layer circuit board: it has very strong anti-interference ability, 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, reliable 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 x 4 System: OS / Windows / Linux Colour: black Material: PCB Size: 22x80mm Package Contents: 2 x Pci-E Expansion Card 2 x Screwdriver 2 x Screw Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.