Expands 4 independent RS-232 serial ports with communication speeds up to 115.2Kbps. High speed SUN1889 16C650 compatible UART controller on-board. Compliance with PCI 33MHz Ver 2.2 & 2.1 specification. Supports both 64-bit 32-bit PCI bus slot and 3.3V & 5V power. On-chip hardware auto flow control to guarantee no data loss. Built-in ±2KV ESD protection for all serial signals. Plug-n-Play, I/O address and IRQ assigned by BIOS. Certified by CE, FCC, RoHS, and Microsoft WQHL approval. Support Microsoft Windows, Linux, and DOS.