That is a very good one for the price. The best ones are well over $100 and this works just as well. It auto calibrates and measure res temp as well. So you put it in either 7.0 or 4.0 calibration fluid and hit the cal button and a few moments later it is calibrated. Piece of cake.
Make sure if you get a good one that you also get storage solution because if the tip goes dry too long it dies. That is cheap too and one bottle lasts a lifetime.