This school backpack is perfect for students on the move. With plenty of room to store tech devices and personal items, the Guardian Backpack provides "Mobile Personal Security" everywhere you go. In a split second, you can activate two high decibel sirens and a high intensity strobe light simultaneously to attract immediate attention to a dangerous or harmful situation (louder than most car alarms). Great security for Children, teens, the hearing impaired and more. Now you can protect yourself when you leave home! Uses two 9V alkaline batteries, which provide over two continuous hours of alarm signaling before the batteries drain. Adjustable chest strap designed to prevent the backpack from easily being taken from the user.