Monitoring tags

The invention provides a monitoring tag for wearing about the appendage of an individual. It includes a self-contained transmitter module that is located in a housing and transmits radio signals to a base unit, for receipt by the base unit if within a predetermined range. If the individual wearing the monitoring tag moves outside this range then the base unit can trigger an alarm or send a warning signal. The housing has an opening for receiving the end of a flexible elongate strap to secure the tag around the appendage of the individual. The strap is attached to the housing inside the opening using a clip, which has structure for fixedly securing it to the strap and structure for fixedly securing it in the opening. Once the clip is attached to the housing it cannot be removed unless a weakened or frangible region between the securing structures is broken.