Features: 1) Infrared sensor detecting motion 2) Chime or alarm is selectable 3) Adjustable sensor detecting space 4) 3 selectable melodies and siren sounds 5) Detecting area: 60 degrees, 8 meters 6) Versatile mounting capability (you can mount it on the wall, place it on a desk or table, or carry it with you) 7) Ideal for protecting homes, offices or shops to announce the entrance of visitor