a microwave - resistant and waterproof security tag for use with food products , especially meat products . the security tag includes a pair of single , open loop conductive traces in between which is disposed a similarly - shaped dielectric layer . this combination is encapsulated within plastic membranes or covers that are sealed at their common edges . the preferred embodiment includes rectangularly - shaped single , open loop conductive traces with rounded corners and with one end of each trace forming a capacitor plate . the width of each trace is at least 1 / 10 of the length of the security tag .