4 in 1 Charging Power Strip - This 12V power strip is equipped with a 12V RV USB socket, a voltmeter with LED digital display, a 12V cigarette lighter socket and a LED rocker switch. Convenient to install and use. Also removable to replace other charging sockets or other suitable devices. Waterproof Dual USB Charging Socket - This 12V USB car socket has two built-in USB charging ports and outputs two outputs: 5V/2.1A and 2.1A (4.2A in total), automatically detects your devices and charges 2 devices simultaneously at optimal speed! Real-time LED Voltmeter With a large digital voltmeter screen that displays voltages from 5 to 48V, you can monitor the battery status of your car or boat no matter the voltage is in normal condition. LED On and Off Rocker Switch - Equipped with rocker style, easy to use. Long service life up to 10,000 cycles. An additional cigarette lighter is suitable for other devices in your vehicle. Overload Protection - Overheat, overcurrent and overload protection;