Abstract: A continuous loop transmitting winding assembly is disposed in one panel and a vertically oriented figure eight receiving coil winding assembly is disposed in a second panel, the two panels being mounted on pivots for swinging gate type movement straddling the pathway to be controlled by a magnetic surveillance system. This arrangement confines the surveillance field to the pathway and tends to follow the passage of an object bearing a marker therealong. No marker detecting backfield is generated. Alternatively, one winding assembly is moveable while the other is stationary thereby similarly confining the field.Special winding configurations are used to reduce interference from third harmonic signals produced in adjacent metallic counters. The arrangement also imposes immunity to signals emanating from cash registers, motors and the like.Door and single gate mounted magnetic and microwave surveillance systems are also disclosed.

Abstract: A device, detectable by automatic means, is concealed within a spring-tong-like housing structure formed from plastic arms joined at one end by a concealed bayonet type locking arrangement that creates a non-mobile joint. The arms are sufficiently flexible to permit their free ends to be pressed together manually thereby engaging a tack shank carried by one arm in a clutch lock concealed in the other arm. The intermediate portions of the arms have reduced structural rigidity such that any attempt to bend the housing structure when the tag is closed will result in flexure of the intermediate portions absorbing the bending forces with reduced communication of shearing force to mating end portions of the arms.

Abstract: An enclosure of tough tear resistant plastic accepts a rectangular lamelliform electronic surveillance component through a slot in a paper panel and secures same by pressure sensitive adhesive to a flat surface of an article such as a phonograph record jacket. A razor edge implement manipulated by authorized personnel serves to sever a sidewall of a raised central portion of the enclosure and engage the component therein for convenient authorized extraction.

Abstract: A transparent security container for an article to be displayed, such as a tape cassette. The container includes an anti-theft device such as a microwave reradiator which triggers an alarm if it enters a microwave field. The container includes a pair of spaced key slots associated with clips for retaining the cassette. A release device at the checkout station permits easy release of the cassette. The container may then be reused.