New mini-Breathalyzer right on your keychain. Never again have a doubt about how much you have had to drink or whether you are legally OK to drive. This mini breathalyzer has a traffic light readout system making it super easy use. Simply blow for 5 seconds then wait. Indicating green and you are good to go; yellow and you may want to wait a while before you go home. If it indicates red then you should hand your keys to friend. This is great reference tool for seeing if you have had just a little too much to drink, but be careful to not rely on this as an iron clad test!

[Via]