Lowest price but good quality, suitable for gift.
wireless alarm, a very innovative product, children will love it.

 

Wear the transmitter (smaller one) on the child or the protege, and wear the receiver on the parent or the owner. Set a distance by the wheel, when the child leaves the parent more than the set distance, the receiver will sound alarm and vibrate to remind the owner.

The working longest distance can reach 30-40 meters when there's no obstacle.

Distance is adjustable.

One-one matching, no interrupt between two units.