These files are hardware designs for the BirthdayGPS, more information is available here:
http://aerofu.com/index.php?products_id=72
or here:
The designs are free open source, released under the CC-BY-SA licence, available here:
http://creativecommons.org/licenses/by-sa/2.5/
Copyright is held by Chris Gough (a.k.a. aerofu.com).
Attribution in derived works must includes both a link to the aerofu.com web site and an appropriate reference the BirthdayGPS brand name.
Derived works must be made available under CC-BY-SA licence version 2.5 or later. It is not permitted to distribute a derived work a more restrictive licence, such as with a "non-commercial" clause for example.