Efest SLIM K1 Intelligent Universal Battery Charger Features Fast Charging Mode: 1.0A Auto Detect Charging Function Low Voltage Activation Function Short Circuit Protection Reverse Polarity Protection Over Charging Protection Piano Wire Spring Provides Smooth Sliding Action - 15,000 Tensile Test Chromium Plated Steel Cathode Insures Low Resistance While Achieving A More Precise Charging Voltage Compatibility 3.6V or 3.7V Cylindrical Lithium Ion Battery 10440, 14500, 14650, 16340, 16650, 17650, 17670, 18350, 18490, 18500, 18650, 20700, 25500, 26650, and More! Specifications Input: DC 5V 1A Standby Current: <20mA Activation Current: 50mA - 100mA 1.0A CC Current: 1000mA ± 10% Auto Recharge Voltage: 4.10V ± 0.10V Auto Cutoff Voltage: 4.20V ± 0.05V CV Cutoff Current: <100mA Operation Temperature: 0°C ~ 40°C Package Contents Slim K1 Charger Body USB Cable Warranty Card User Manual **PLEASE NOTE THAT THERE ARE NO BATTERIES INCLUDED WITH THE CHARGER. ANY PICTURES OF BATTERIES SHOWN IN THE IMAGES ARE SOLELY FOR DEMONSTRATION PURPOSES ONLY