Add 1 parallel port & 2 RS-232 serial ports to your standard or low-profile computer through a PCI Express expansion slot Native single-chip, single lane PCI Express chipset delivers true PCIe performance Standard & low profile/half-height bracket included to ensure fitment in any system Easy to install & use with full step-by-step instructions saving time & hassle The PEX2S5531P 2S1P PCI Express Card turns a PCI Express slot into two RS232 (DB9) serial ports & one Parallel port. The adapter card features a native PCI Express single chip design that means that you can take advantage of full PCI Express capability, providing enhanced speed & reliability while reducing the load applied to the CPU by as much as 48% over conventional serial cards which use a bridge chip design. Compatible with a broad range of operating systems including Windows® 2000/XP/2003/ Vista™/ Windows 7/ Server 2008 R2 (32 & 64-bit), Linux Kernel 2.6.11 & up, & MAC OS 10.4, this 2 Port Serial 1 Port Parallel PCI-Express Card also features an optional low profile/half-height bracket that allows the card to be installed in virtually any computer case, regardless of the case form factor. This product is a replacement for our PEX2S5521P card. Backed by a Star Tech.com Lifetime warranty & free lifetime technical support. What’s in the box 2 Port PCI-Express Serial Card Parallel port (with ribbon cable) Low Profile Brackets Driver CD Instruction Manual