hello, I acquired this article once to my parents (80 years +). Once we convinced them to put the tag on their keyring, it works very well. Small flat, however for people with difficulty hearing high-pitched sounds, so do not buy if the persons concerned are in this case. Acquired a second time at home (parents + 2 teens). No worry to remember the correspondence letters and colors: you can easily determine a criterion, such as Mom and Dad 1st child etc, which would correspond to A, B, C etc ... Last thing, it works throughout the house, even through walls or floor to another, and as others have said, do not change the remote site! And you'll be glad to have bought this article the day you're super hurry and you can not find your keys! :-)
