Last night was my nephew’s 30th birthday party and I took along my alcohol tester. We all had a great time checking our levels after having different amts. to drink. Today I went to my sisters for a football party and took it along. I tested my level before I left before which I knew would be 0.00 since I had not had anything to drink yet. After the game I retook it and it read 0.07 as shown in the picture. I did not think it would be that high since I only had a large coffee with one shot of Rum Chata in it but everybody has different responds to alcohol. Before testing you need to read the instructions carefully. For accuracy you need to wait 15 mins. after drinking to test. In consecutive testing you need to wait at least 1 min as there maybe residual left in the mouthpiece.or blow clean through for 3 seconds. Very simple to use..install 3 AAA batteries in to compartment in back..Press button on front..wait for beep to start blowing..will beep again to stop..will test results and display. If level is high will state high and also has a picture of a car that will show a circle with a slash through it if you should not drive. You should only use as an indication for the presence of alcohol. This is a good device to use if you have teenagers, breastfeeding, or as an indication of how much alcohol you have in your system. We all know how destructive it is to drink and drive..not only for yourself but for your love ones and anyone out on the roads. I received this product at a discounted price. All my reviews are based on my own experience and evaluation of the product so that others can benefit in finding quality products that meet their needs & expectations.