4 HOLE ALUMINUM PANEL: Dual USB Socket + Voltmeter + 12V Outlet + Toggle Switch. Premium aluminum panel make it stronger, provides over-heated, over-current, over-charging protection, more safety for normal use (With connection wires and screws)REAL-TIME LED VOLTMETER: This switch panels for trucks with a digital voltmeter display that shows 9-24V voltage, you can check the voltage status of the battery on your car or boat.EXTRA CIGARETTE LIGHTER SOCKET: The additional cigarette lighter socket is portable for other appliances in your vehicle. Any standard cigarette-lighter style plug will work.WIDELY USING: Fits for Car, Boat, Marine, Truck, ATV, UTV, RV, Camper, Battery Box, and other 12-24V Devices, also for Mobile phones, Tablets, GPS, Digital cameras, PDAs, and Other USB Accessories.EASY TO ASSEMBLE & INSTALL: Swivel the button to loosen or tighten to replace the parts you want, easy and convenient. It also allows you to draw your own wiring diagram to get it the way you wanted. DI