Master control chip 8749: Provides high-bandwidth and low-latency transmission capabilities, meeting high-speed data exchange and high-performance computing requirements. It can be configured in bus modes: x16, x8, or x4. Its built-in DMA engine ensures reliable and stable data transmission. 15U gold plating; LED indicator light; active fan radiator. 2 ports SlimSAS , SlimSAS ports can be connected to external graphics cards/network cards/U.2 hard drives. Dip switch adjusts the SlimSAS ports to switch between x16/x8/x4 modes. Reserved screw holes are available for 2280/22110 NVMe hard drives. GPU 6-pin port, provides auxiliary power when fully loaded. Color: Black Material: PCB+Metal Package Contents: 1 x PCIe3.0 expansion card Only the above package content, other products are not included. Note: Light reflection 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.