Using high-quality components, intelligent dual IC program control circuit, chip motherboard design. Charger with the flow, overcharge, short circuit, lightning, temperature, pressure, electromagnetic field protection and other functions, constant current output, full stop automatically. 4.2V 1A lithium battery charger for the aircraft model aircraft, remote control airplanes, electric cars and other toy model aircraft / toys polymer battery pack. ABS plastic, exquisite appearance, high temperature wear-resistant and durable. Low loss, fast transmission, power supply with an output short circuit protection, overload protection, overheating protection. Product Name: Lithium Battery Charger. Input voltage: AC 100-240V. Output voltage: DC 4.2V 1A. Output Current: 1A at constant charging current decreases. Voltage Frequency: 50 / 60Hz. Output ripple: 100MVP-P. Efficiency: 85%. Output line length: 1M. Weight:67g/2.34oz. Output interface: 5.5mm (routside diameter) * 2.5mm (inner diamete) Plug polarity: the positive (+) outside negative (-). Scope: 3.7V4.2V single string rechargeable lithium batteries, polymer battery pack. Instructions for use: Please confirm before use if size and polarity DC power plug your devices with the same. Keep dry and ventilated environment, avoid hot and humid.