I'm very careful about keeping track of what I have had to drink to make sure that I am not at risk for a DUI. I decided to invest in this device as an added layer of protection - to make sure my mental math is correct. It is easy to use and appears to be quite accurate.
It only worked for 1 year, now gives say 0.00 when I'm clearly drunk. I know because I have breathalyzer in my car. I've changed batteries and am unsure why it wont work. Only used 65 times total. Save your money.
I bought this one after owning the keychain for 8 months. This one is way more accurate, more than .02 times accurate than the keychain. Worth the money. On the keychain you will blow .02 times higher than the pro.
I bought this about 6 weeks ago, and have used it once. It worked great and will provide me with the resource that I needed to perform on the spot testing when the need arises.