A method and a device for detecting intrusion into or tampering with contents of an enclosure.
More information about the Tamper patent (pdf).

Granted Patents:
US7659816, 2010-02-09 
SE528760, 2007-02-13
EP1886286, 2012-07-11
CA2607731, 2015-04-21
AU2006248151, 2006-05-18
MX274141, 2010-02-15