Most suitable for spirit washes but can be used for beer, cider and wine. Measures Specific Gravity (SG) or density of the brew not alcohol amount. Has Specific Gravity Scale from 1.100 to .975. Length is 30cm making it too long for our hydrometer testing jars. This requires you to open your brew to test internally which is low risk for washes but high risk of infection for beer, wine and cider. Red band marking for spirit washes at .990 or lower. Essential tool to measure when fermentation IS complete rather than hit and miss method with airlock activity. If you are making a spirit wash you should be confirming your wash has reached .990 before trying to clear the wash for distilling. If using more sugar (7 and 8kg's/25litre) then your reading should go higher on the scale, ideally approaching .980.