Review on 🚗 FNSHIP Driving Doze Reminder with Vibration Alert - Car Anti Sleep Doze Nap Reminder Ear Warner - Anti Sleep Alarm by Matt Nichols

It works if you understand its limitations. It works by measuring head tilt, which means you need to sit up straight and keep your back straight. If you sit back, it will NOT work. It doesn't work if you blink too much (tiredness). It ONLY works when you tilt your head forward, and you need to "calibrate" it by fitting it to your ear to make it work with a slight forward tilt. when you nod off and your head is tilted forward. The on/off toggle switch is pretty noticeable when you get tired of the buzz. This device should work well in large trucks where you sit upright. But its usefulness in private transport is highly questionable.