A safety alarm is small enough to fit in your hand, has a key chain or wrist strap so it's easy to carry, and some even come with a mini flashlight built in.
The function of a portable personal security alarm is to distract criminal activity and alert people in the surrounding area of a serious situation or emergency. You can get details about siren song security alarm online through various websites.
Most personal alarms can sound off within a ¼ mile. Others are within a short distance. Many versions come as an electronic security device and others are aerosol devices that won't cause any blast injuries to the ear.
Both types of personal safety alarms are easy to carry and very easy to operate. With a simple push of a button, the aerosol cans emit compressed gas that when pressed will pierce the eardrums with about 105 to 140 decibels of power and deter a personal attack against anyone.
Electronic alarms such as the 2 in 1 personal door alarm are activated by the push of a button or the pulling of a pin. Other models such as the 3 in one sports strobes or a keychain alarm have pull pin systems that when taken from the victims hand will sound off. However, a personal alarm will not disable an assailant. Combine a safety alarm with a pepper spray or stun gun and you have double the chances to deter the attacker.