This is a security sensor made by YKK, designed to be attached to genuine window glass. It reacts to the sound of breaking glass, not vibration. Although it is unused, the box is slightly dirty due to long-term storage, so please refrain from purchasing if you are sensitive to this. I replaced the batteries with new ones today and confirmed that it works. It cost 5000 yen each at the time. This product is discontinued, so it's unlikely you'll find the same one. There are three in the set, so I think you could put two on sliding windows and one on a single-pane window. It will be shipped with new batteries (one was opened for testing), so how about using them for crime prevention, such as against burglars? It makes a rather loud noise. Thank you.