We have all had the gut-wrenching feeling of turning around in a busy street and finding that our child is nowhere in sight. Electronic Child Leashes Now this could be prevented with the new improved Child Guard. Worn by the child, the cartoon animal-shaped transmitter sends a constant signal to the receiver, which is held by the adult. The signal is adjustable - from a distance of 6 to 30 feet, so when the child goes beyond the set distance, the adult's receiver starts to beep, letting them know that the child is starting to wander off. The Child Guard is worn on the wrist of the child.