Apparatus and method for tracking an object includes a transmitter for generating a signal, and a receiver for receiving a signal generated by the transmitter. Receiver, when the distance between the transmitter and receiver is larger than a predetermined value, generates an alarm signal. The receiver is held in the holding element of the wristband, on the one hand the transmitter is fixed to the object. Receiver, only when it exceeds the predetermined distance is programmable to generate an alarm signal. Retaining element includes a plurality of retention features optionally This allows holding a plurality of receivers in a single retaining element. To each pair of transmitter / receivers, by assigning a unique identification code, each receiver can be programmed to communicate with only one corresponding transmitter. Unique identification code, expire after use, so that each transmitter can communicate only with a single receiver.