The kit includes a PCB and all components necessary to build the adapter unassembled. Tools are not included. This kit is really easy and will only take 15 minutes to build even if you've never soldered before.
Please note that the adapter does not include an XBee module they must be purchased separately. Check out this page for a comparison of all the XBee's available. If you want to connect this up to a computer's USB port you'll need a FTDI cable or FTDI friend (also not included)
For more information check out the project page for instructions documentation tutorials and example code!