AT118 LED Alcohol Tester Breathalyzer Keychain (0.20% BAC Max)

Pros: it's precise, at least i used it one night and it said i wasn't drunk, then a policeman stopped me to check my BEC and gave a ngative.
it's easy to use, just blow
a great source of ethanol semiconductor sensors for hobbyists
It can be perfectly used in Spain, cause it't calibrated fot the actual limits here

Cons: a bit hard to understand the instructions
it sometimes doesn't want to measure and you have to reset it
a bit big to be a keychain
better if it could be calibrated

Other: hard to find a cheaper solution to check your BAC, i think that almost every drinking person should have one of these.

Pros: This is a great cheap little device that can analyse your breath, it feels sturdy, and the LED light inside of this little device is quite useful.

Cons: It isn't really the precise. It only has 3 lights, and by using it around 3 times being really drunk it still says i am sober. It is fun to do however.

Other: cheap little device, works OK, not that precise, but you get what you pay for.