Car Styling Car Safe Device Anti Sleep Drowsy Alarm Alert Sleepy Reminder for Car Driver To Keep Awake Car Accessories Description: Put it behind your right ear, Alerts when the head lower in the degrees of 15 to 20 Especially suitable for long-distance driving or night driving. ON / OFF switch. Powered by AG3 button cell batteries(included). Driver safety alarm can help prevent accidents caused by driver's sleep when driving. It is 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 tim Matters needing attention : Check whether the product is working properly before use Turn on the switch Examine whether it is in the normal operation:it beeps when you are leaning your head forward and makes no sound while sitting straight , it is at normal state Please turn off the swith and put it away when you do not use it Keep it away from High temperature and damp The product will only remind you when you doze off, it will not stop you from dozing off. So don't be tired driving, safety first. Package Contents: 1 Pcs