I need to have a means to check my BAC before driving. I am a very good driver - in almost 30 years, I have never so much as dented a car I was driving except the one time I was stopped at a traffic light and got rear-ended. That said, just because I think - even *know* - that "I can drive", the law may say otherwise. With limits reduced to a meager 0.08%, I am entirely positive I have driven over that limit before and I don't want that to happen again. I cannot afford a DUI. I shopped around and immediately discarded all of the cheap-o keychain options. I am not interested in fail/pass (read: alcohol present vs. not, at all) device. I want an accurate measurement. If I am at 0.08%, or above, I look to either find another mode of transportation or wait it out some, depending. In purchasing this device, I spent more than I had anticipated, but this is an occasion where quality cannot be sacrificed. It arrived quickly after ordering. Within the box was a nice carrying case, the device, an instruction booklet, a registration reminder, a pair of AA batteries, and a half-dozen individually sealed mouthpieces. I reviewed the instruction booklet. It is front-loaded with a few pages of general information RE: alcohol consumption. After that, there are a couple pages dedicated to the operation of the device. The instructions were stone-cold simple except for ONE thing. It made reference to pressing the "Power Button" which is, in fact, the "Start" button. I took a measurement and it seemed to operate just fine, registering a solid 0.00% result, which is good since it is still the middle of the afternoon and I am not an alcoholic. The device is solidly built and everything fits nicely in the case, which zippers shut. It can easily fit in one of the several storage cubbies in our car. I intend to throw a spare set of batteries in there and leave it in the vehicle. Anyway, my wife and I have an active social life and, quite often, it involves some booze. I'll probably be using this device once a week. I will update this review with tales of "actual usage" as they unfold. I may just "calibrate" it tonight, for kicks. There is nothing I see, so far, though that renders this anything less than a five star product. Only tips are: Have spare batteries. Register the product online (takes 30 seconds). Wait 20 minutes after your last drink before expecting an accurate measurement. Be prepared to send it off for calibration once a year. That should do it. Good luck and stay safe and out of trouble! EDIT: The night I purchased the device, I drank some beers and measured the results. They were exactly what I expected them to be. Measuring after waiting 20 minutes after each beer yielded increasing results. I did this for eight beers. About two hours after no longer drinking, the results started to go downward. I am confident I will not only have a good measurement when it comes time to drive, but I will also develop a better sense of what different levels of buzzed/drunk translate to in terms of raw BAC numbers...and how long those numbers take to diminish after stopping drinking for the evening. This is good information to have. EDIT2: After using this device for some months, I absolutely love it. I have basically trained myself to enjoy the evening, but end it under the legal limit. When I go to the car, I check my level and, almost without fail, I am able to predict what it is within 0.005...just based upon what I have consumed and how I feel. No more guesswork. No more risk. I cannot recommend this enough. I have had friends witness my use of the device (and the eerie accuracy of my predictions..."I feel like about a 0.065"...BOOM!) and they have been quite impressed. Hopefully the behavior will rub off on a few of them and they, too, will render themselves immune to unnecessary trouble. EDIT3: 6/26/2015. Well, some nasty person broke into my Jeep Wrangler while I was attending a rock concert with my son, destroyed my locked glove compartment (but couldn't get it open), cracked open the locked middle console, and stole my BACtrack S80 (among other things). I just ordered $800 worth of Tuffy gear (secure glove compartment, middle console, and rear compartment), so that's not going to happen again, but, more pertinent to this product, I am purchasing the same exact BACtrack S80, again. That is how good it is. Meh. It was up for calibration, anyway.
