Indispensable high quality tool for measuring sugar content (Brix) of fruits to determine maturity. Also used to monitor the Brix in plant tissue (leaves and stems) through the season. High Brix indicates adequate nutrition and is an excellent indicator of fertilization success. Plants with high Brix (reading above 12) sugar content have good "immune systems." Squeeze the sap from fruit or leaves onto the glass plate, then turn towards the sun, and read the Brix" in the viewer. Comes with chart of desirable Brix for common crops. Meter is accurate to within +/- 0.2 Requires appropriate care. Automatic temperature compensation. Measures 0"-32" Brix.