Streetwise Nap Zapper - Personal Security Alarm for Night Safety

This was purchased more as a gag gift for someone who fell asleep at the wheel once. Unfortunately, the motion sensor isn't really sensitive enough to catch you when you've dozed off unless you're the kind of person to keel all the way over while driving. When you're holding the device, it seems to want to beep a lot as you move it around in your hand. However, once worn behind the ear as intended, you really have to move quite a lot for the unit to beep - the required angle for the device to register a warning is greater than the typical deflection your head would experience. If you pitched over that far, you'd wake yourself up, no alarm needed.Great concept, and very inexpensive, but sensitivity needs to be increased for this to be anything more than a gag gift (that doesn't actually work).I would not wear it to work to announce to coworkers and customers that THAT BUZZING SOUND YOU HEAR IS ME--I FELL ASLEEP--or bent my head down. But I do have it in the car, for when I am driving alone. Its a little big, so I would not wear it in the presence of anyone, only when alone and watching tv or on the computer or in the car..bout it tried it out and it worked and then went silent .and didn't work at all. I rote a email to the compuy and told them I bout it for a friend who had fell a sleep at the weel more then once and I wanted to return it for a replacement and then I got an email back tell me that thare was no need to send backand thay would send me one free of charge the new one works just fineBought this for a friend of mine. He said it was great while it worked, unfortunately fell apart within a week.This was a gift and I'm told it works like a dream! Apparently it REALLY does keep you from drifting-off. The very second your head starts to tilt past a certain degree, it emits a high pitch. GREAT idea for those who drive long distances.I love this thing. It works great. Apparently someone else loved it too cuz they borrowed it and never returned it. Sure wish I had it now. I would definately recommend it to anyone.Fine workmanship and order arrived as promised.Bought this for my dad who is a truck driver, couldn't get it to work at all! He was really looking forward to something like this, will try another product.