digital level

anyone know what hardware is (or might be) used for this?

http://www.sears.com/shc/s/p_10153_12605_00948295000P?vName=Gifts&cName=AllDads&sName=Father&psid=FROOGLE01&sid=IDx20070921x00003a

i’ve searched around, but can’t seem to find anything about the internals…

thanks,
isaac

probably something like this for the gravity aspect, perhaps a pair of them.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=475-1269-1-ND