These little gizmos are useful if you have concrete walls and you want to hang pictures.They aren't perfect, but you can't really fault this particular brand for that; none of these things are perfect.But If you use them with a little bit of practice, you can usually get them to stick into the wall. You must use a hammer with a striking surface large enough to hit all three mini-nails at once, and not strike too hard. Occasionally, they cause some damage when you take them out, so you want to be careful.The easiest way to hang a picture with these is to attach to the little plastic hook a length of picture hanging wire.