The Mace Brand Personal Alarm Keychain emits a 130dB shriek that instantly brings attention to the user. To use, simply depress the button on the front of the alarm which will then deter any attacker or intruder but can also function to draw attention to you if you need medical attention or help. To deactivate the alarm, depress the button on the back of the alarm. The alarm is easy to use and ideal for school age children.