Abstract: The invention relates to a device (10) for making an antitheft link between two objects, the device comprising an envelope (20) of heat-shrink plastics material whose walls are locally brought together along a common generator line (23) to form both a main compartment (24) which is open at both ends and which is designed to envelop one of the two objects to be connected together, and an auxiliary compartment in which an elongate pin is disposed. The device has a wall (31) provided on the other object (30) with a narrow longitudinal slot (32) formed therein that is open at one of its ends, said slot being dimensioned to enable the envelope to be inserted level with its common generator line (23) so that the elongate pin co-operates with the wall (31) to provide the link between said other object and the envelope which has been heat-shrunk on the first object, and to enable the inserted envelope (20) to be locked into place by means (36) closing the open end of the slot (32).