This 4 Port USB to RS232 Serial Hub lets you connect up to four RS232 serial devices to your Mac or PC laptop or desktop computer through a single USB port, as though the computer offered built-on DB9M serial connectors.The RS232 Serial Hub is compactly designed to preserve valuable workspace, and is bus-powered to eliminate the need for an external power adapter.A cost-effective solution that bridges the compatibility gap between modern USB-capable computers and legacy RS232 serial peripherals, this dependable USB/RS232 Serial Adapter hub is backed by StarTech.com's Lifetime Warranty.The StarTech.com Advantage- Add four additional RS-232 serial ports to any computer with a free USB port- Provides serial connectivity to legacy free systems lacking RS-232 serial ports- Supports wakeup and power management modes