... key to operate. Function is as follows:LCD display FunctionM1: Measure Measure the leaf areaM2: Record Show recordsM3: Delete Delete recordsM4: ... Width Measure the leaf widthM5: Length Measure the leaf lengthM6: Send Send data M7: Other ... measurement, unit is mm2. Press the "V" key again and shows the average:If measure again ,press "Confirm"key,the LCD ...