Abstract: An anti-theft device includes two groups of elements, each group being composed of a plurality of elements flexibly joined to each other by offset cylindrical joints; both of the groups are flexibly joined at one end to a central link, and are fitted with a disengageable fastener at the opposite end; when used, the opposite ends of the device are fastened to each other to form a closed loop round an object that is to be secured against theft; the fastener is designed to keep the device locked in its closed loop configuration so as to prevent unauthorized breaking of the loop; when not used, the device can be folded up into a neat, compact configuration in which the two groups of elements are folded up and arranged side by side.