This is DC-DC 4.5-40V To 5V 2A USB Charger Step down Converter Voltmeter Module, a combo of 2A Charger and voltage checker.

The module converts input of 4.5-40V into a very stable 5V 2A output. The device features a USB port through which you can charge your phone. While charging your device please consider that the output of this device is regulated at 5V 2A.

Simply connect this device to the power supply, the voltage can be detected in real time. When you need the phone, IPAD, MP3 and other digital products to charge, click the ?Output Enable? button, then USB power indicator lights up and it will start supplying 5V 2A at its output.

When you need to turn off the voltmeter, click the ?Low Power? button, then enter the ultra-low-power standby mode, USB output corresponding shutdown.

It accepts wide input voltage as from car/battery car/motorcycle used for monitoring battery voltage; measure the voltage needed for a variety of occasions. The output current capability 5.0V/2A, enough to meet a variety of USB devices.