There is described a tamper-proof fastener for use in security applications, the fastener comprising inner and outer members interconnected by flexible straps. The inner and outer members each comprise a leading end, a shank, and a trailing end, the shank of the outer member consisting of two substantially...http://www.google.co.uk/patents/US4312614?utm_source=gb-gplus-sharePatent US4312614 - Security fastener
