4 BAY BATTERY CHARGER - With 4 independent charging slots, our smart charger support to charge for different types of DC 3.7V cylindrical lithium batteries simultaneously: 18650 18659 20650 18650 16850 Li-ion Battery. SAFETY GUARANTEED - This battery charger is equipped with an advanced charge management circuit. Moreover, It is designed with security protection settings, the charger can effectively prevent reverse, short circuit, overcharge, over-discharge, and over-current damage. Just use it without any safety anxiety. MUTI-FUNCTIONAL LCD DISPLAY - This Intelligent battery charger With a large and clear LCD display, which can show voltage, current, charging time, battery type, internal resistance and battery capacity data, so that you can get the charging data easily.