Adapter is built on the Prolific 2303 chipset and works right out of the box on my MacBook Pro (OSX 10.6.8). I used it to connect to my network security appliances that have only a DB9 connection for console. Installed the latest drivers from TrendNet's website and used Z-Term for a terminal emulator. Z-Term immediately recognized the /dev/tty.usbserial device and connected with no issue.