The Keto diet has helped many lose weight and get fit. The GDbow Ketosis Analyzer is a ketone breath analyzer that takes the guesswork out of the process and helps you maximize your fat burning rate. It has a LCD display with color coding to show readings. When your reading is 0.0, that means you are not in ketosis while numbers close to 3 means you are in the optimal zone.
This particular model ships with 10 replaceable mouthpieces. You can find out more about it here.