Sper Scientific 300003 Refractometer, Brix: 0 ~ 80% Sper Scientific 300003 Sugar Refractometer 0 ~ 80% portable refractometers work in ambient light with no battery or other power source necessary. Perfect for very high sugar content products such as jam, marmalade and syrup. 0-50% & 50-80% brix Resolution 1% Accuracy 1%