Abstract: An anti-theft device (10) for deterring theft of a protected article has first and second housing elements (12,16) and a locking mechanism (20) for securing a male portion (17) of the second housing element (16) to a female portion of the first housing element (12). The locking mechanism releases the male portion from the female portion, when actuated by an unlocking device operated by an authorized person. A thermally controllable element (36,42) assumes a first position during normal temperatures, wherein the locking mechanism (20) is kept in a locked state, and a second position when heated to temperatures above a predetermined limit, wherein the locking mechanism is caused to release the male portion (17) from the female portion of the first and second housing elements (12,16).

Abstract: A sensor for remote detection of objects in a surveillance zone (10) is preferably intended to be used in an article surveillance zone, which further has at least one transmitter means (11, 13) and at least one receiver means (12, 15) for transmitting and receiving, respectively, electromagnetic radio-frequency signals in the surveillance zone, and at least one modulating means (16) for generating a modulation field in the surveillance zone. The sensor is arranged to transmit an electromagnetic reply signal at the reception of electromagnetic energy from the transmitter means, said reply signal being dependent on the modulation field and being receivable by the receiver means. A magnetic element (23) is arranged in a sensor body (21; 101, 102), the magnetic properties of the element being controllable by a magnetic field acting as the modulation field, wherein the amplitude of the reply signal from the sensor is controllable through the magnetic modulation field.