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's Lifetime Warranty.