There’re many different ways this alarm can be used. Personal Alarm : Carry it in a purse/pocket or attach it to your belt. In an emergency pulling the cord will activate the 130DB alarm and flashing light which will scare off a would-be attacker. Purse/Briefcase/Backpack Alarm : Clip cord to your belt or wrapped around your wrist with the alarm placed inside your purse/briefcase/backpack. Alarm will sound if someone attempts to take it from you. Door/Window Alarm : With the door clip, the alarm will sound and scare off a would-be intruder in an attempted entry. Laptop Computer Alarm : Place the same door clip under your property, if someone picks up the object, the alarm will activate. As an added deterrent, an alarm warning decal is included. Requires one 9 volt battery (not included.)