SIIG 4-Port Serial PCI Express Card Model JJ-E40011-S3 Type: PCI Express to Serial Port Card External Ports: 4 x Serial Ports Operating Systems Supported: Windows 7 (32-/64-bit) / Vista (32-/64-bit) / XP (32-/64-bit) / Server 2003 & 2008 (32-/64-bit) / 2000 Specifications: Regulatory approval(s): FCC Class B (DoC) & CE RoHS-compliant Chipset: SIIG CyberPro, V3.0 (Oxford OxPCIe954) Built-in 128-byte FIFO buffers dramatically increase data transmit/receive speed, especially under Windows multitasking environment 4-layer PCB board: separate layers for data & grounding. Greatly reduces signal noise & loss. Delivers more reliable high-speed data transfers Enhanced bracket design to prevent bending. Connected to PCB with washered screws for a more secure connection Weight: 1 Parts: 1 year limited Labor: 1 year limited