A NEW electronic device that allows families to monitor the whereabouts of young children or elderly relatives is being put through its paces in Putuo District.

Developed by China Telecom, the cellphone-like gadget can be programed to alert worried parents if their children wander outside a predetermined area, said authorities in the Caoyang neighborhood, where a trial is under way.

If the person carrying the device goes beyond an “electronic fence,” the system will call the monitor’s phone or send them a text message. The exact location of the device — which can also hold the phone numbers of family and friends — can be monitored on a dedicated website, its developer said.