This deluxe hydrometer for beer features a built-in thermometer with correction scale that allows you to instantly correct your hydrometer readings for temperature. All hydrometers are calibrated to read correctly at a particular temperature, and temperatures above or below that point require that you add or subtract from your reading. Like the basic model, this deluxe hydrometer also features three scales - Specific Gravity, Potential Alcohol and Brix (Balling).