PX-420 - Brainboxes PCIE 3+1XRS232 PCI Express card provides 4 industry standard 9 pin RS232 serial COM ports, fits in any PCI Express slot e.g., x1, x4, x8 or x16 lanes. - Fits in x1, x4, x8 or x16 PCI Express expansion slot - 256... $554.00 $307.78