This range of serial boards has been designed to meet the requirements of the new 3.3V PCI slots (including PCI-X) whilst remaining backwardly compatible with the long-standing generation of 5V PCI slots. L versions are "low-profile" and are fitted with a 60mm bracket as standard. An 120mm bracket is included so L versions can be used in standard systems too. Buy these boards for a cost-effective and flexible solution when adding serial ports to a PC.