If you need a cheap USB to serial adapter then look no further. I went through a few eBay ones but it looks like a lot use knockoff chipsets and I found issues when using OSX and Windows 7 with them. Plugable are recommended by the chipset manufacturer and only use genuine chipsets. They are also cheap and I have tested them working on OSX and Windows 8!
For a full product break down and drivers see:
Please use my affiliate link below if purchasing to help me cover domain renewal costs if you found this helpful. Thanks!