Portable surveillance system e.g. for shop-lifting prevention

摘要

The system includes a housing (2) through which a conductive detection wire (4) is led. When an insertion element (5) is inserted into the housing the loop (4a) of the detection wire is retracted. A locking element (6) locks the insertion element and is attracted by a magnet (M) which allows the locking element to be moved to release the locking element. Preferably, the insertion element includes a projecting part which engages the locking element to prevent the release. The insertion element is pushed once into the housing to release the engagement between the locking element and the projecting part.