Instruct: Classify Amazon reviews into positive or negative sentiment
Query: breathkey review

if you like breathalyzers and you want one you can rely on, do not buy this product, buy a real full size breathalyzer. trust me, just because its small and it fits on your keychain does not mean this product is worth it. ive used it side by side with a professional breathalyzer; the results were dramatic. the breathkey was always under the correct result. if you purchase this product DO NOT use it as a means of deciding whether or not you should be driving. it is a novelty item, like all other keychain breathalyzers.