Features: Real time detection: test voltage, current and charging capacity. LCD display with multiple data, easy and clear for readings. DC3-9V voltage test range, 0-3A current range, 1% accuracy. Voltage alarm function: when the voltage is higher than 5.3V(display H) or lower than 4.7V(display L). With data storage function: memorize 10 groups of capacity data. Quick capacity data review and zero clearing function. U-disk current detection and USB interface voltage detection. Improve the charging efficiency and protect the charging equipment.