Features: Support PCI-Express Base Specification Rev3.1； Compliant with NVME 1.2a；Compliant with SFF-8643 Specification Version 3.5 With 4 U.2 Nvme SFF-8643 expansion ports. This product can only be used on PCIE slots- that support PCIe split. Support PCI-E4.0-, support 2U chassis, high-speed lossless- transmission, strong compatibility Application:for Servers- for HBA-(Host Bus Adapter),Data Center ,Storage Racks, Storage Controller, Servers-RAIDs(Redundant Array of Independent Disks) for Routers Specifications: Bus Type: PCI-Express3.0 x16 Number of Ports: 4 Port Dimensions: 129.3x46.4mm/5.09x1.83in Access bus: PCIe x16 Interface type: 4 U.2 (SFF-8643) Supported devices: 4 NVMe SSDs Scope of application: server- RAID-, storage controller, data center, etc. Host slot: PCIe x16 System support: Windows-, Linux-, UFEI, VMware-, and other systems- Storage temperature: -65 ℃ to+150 ℃ Industrial grade temperature: -40℃ to+85℃ Package Includes: 1 x PCIe x16 to Mini SAS HD-(SFF-8643) 4-port Adapter 1 x User Manual 1 x Low Profile Bracket- 4 x 50cm SFF-8643 to U.2 SFF-8639 with 15-pin Sata- Power Cable(Optional) note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-2mm error due to manual measurment.