4 in 1 Charging Socket Strip - This 12V socket strip is equipped with 12V USB socket + LED digital display voltmeter and 12V cigarette lighter socket + LED rocker switch. Convenient for installation and operation. Also removable to replace other charging sockets or anything else that fits. Waterproof Dual USB Charging Socket - This 12V USB car socket has built-in dual USB charging ports, dual output ports: 5V/2.1A and 2.1A (total 4.2A), recognize your devices automatically and charge 2 devices simultaneously at optimal speed! Real-time LED Voltmeter with - With the large digital voltmeter display that shows 5-48V voltage, you can monitor the battery status of your car or boat when the voltage is normal. LED On Off Rocker Switch - Designed with rocker style, easy to use. Long service life up to 10000 cycles. The extra cigarette lighter socket is portable for other devices in your vehicle. Overload Protection - Overheating & Overload Protection; This dual USB charger socket is also