Need help to use on Mac OS X 10.10.
There is no mentioned on the official website of compatibility with OS X 10.10. I have downloaded the CD package, and indeed, there is a MAC driver, but compatibility is not specified. This means the only thing you can do is test it by yourself.
Download package: http://www.nexxtsolutions.com/us/nano-lynx-wireless-n-usb-2-0-adapter#downloads
Extract the archive and then locate the Macintosh folder.