This is a great product for the elderly or absent minded prone to losing keys or purses. The problem is that the batteries only last 6 months or so, and are expensive to replace if you have several tags. The batteries go flat with no warning, in contrast to the item description, and then the tag just doesn't work, so if the item is mislaid it stays mislaid. As a result, to be sure I have had to put 2 tags on each item with one set of batteries changed every few months.
The other problem is that if the item is put into a metal container, then the tag does not work anyway. So one is never sure whether the item is stolen or lost outside the home more than 100 yards away, is in a metal container, or the battery is flat. This can lead to unecessary stress until the item is found again.