This refractometer from Learn To Brew is for measuring the sugar content of beer and includes an automatic temperature compensation of 10 - 30 degree Celsius. No tools are needed for calibration. This refractomerter can replace your homebrew hydrometer and is much more precise. It is ideal for brewing and is extremely easy to use. Just drop some wort or beer on the lense and gaze through the eye piece to measure the sugar content in degrees Brix, which is easily converted to Specific Gravity. A conversion table from Degrees Plato to Specific Gravity is included. This item is of premium quality and at an exceptional price and is packed in a protective plastic case. 0 - 32 Degrees Brix, RESOLUTION 0.2% ACCURACY 0.2% (You won't find that in a homebrew hydrometer)Plus, with the purchase of this item you will receive a complimentary copy of Learn To Brew: Recipe Formulation Made Easy computer program. Be sure to see the other beer, wine, and kegerator related items sold by Learn To Brew.