Sound Alert Anti Sleep Alarm Driver Alarm for Drivers Security Guards Brand new anti-sleep alarm for drivers!. Driver safety alarm to help prevent accidents caused by falling asleep at the wheel. Perfect for anyone who needs to keep alert on duty, like drivers, guards, machine operators, and even students Safe for long drive and drive at night. Especially suitable for long-distance driving or night driving. It is guardian angel for drivers. Easy to use and comfortable to wear for a long time. Work on the study of human body balance Main Function: Anti Sleep Alarm. Alarm mode: sound alert. Dimensions: 75 x 22 x 15mm. Angle of Protection: 15~ 30. Battery: Replaceable button cell battery. Life Time: 30,000 nods