BLUE-----Narcolepsy Driving Alarm Driver Alertness System Nap Zapper Anti-Sleep Alarm Driver Alert Sleep Warning Device Driving Doze Reminder Hanging On Back of Ear (Black) Safe Driving Sleep Alarm Device.The NOD-Stopper is a sleep warning device that you wear over your ear. The NOD-Stopper: The NOD-Stopper helps prevent automobile accidents caused by falling asleep behind the wheel. This device is lightweight, it's comfortable and you can wear it even while wearing glasses!