4 in 1 Marine Car Charger Socket Panel, 12V 4.2A Dual USB Charger Socket Power Outlet & LED Voltmeter & Cigarette Lighter Socket & LED ON Off Rocker Toggle Switch for Car Marine Boat RV Truck
Brand: Linkhood
Noted: Wire diagram not including
There are + & - on each module except the three-prong switch. One prong is brass, the others are silver.
About this 3-prong switch, the brass prong is negative and the center is positive in, the outer silver prong is supplied positive.

Specification:
Style: 4 in 1 Charger Socket Panel
Color: Black Shell & Blue LED Light
Material: ABS
USB Output: DC 5V/2.1A&2.1A (total 4.2A)
Power Outlet: DC 12V
Voltmeter Display Range: 6 - 24V
Toggle Switch: 20A 12V DC
Package Weight: 135g / 4.8oz
Cigarette Socket Dimension: Approx. 1.18" * 2.13"(30mm * 54mm)
USB Car Socket Dimension: Approx. 1.18" * 2.05"(30mm * 52mm)
Rocker Toggle Switch: Approx. 1.18" * 1.57"(30mm * 40mm)
LED Voltmeter Dimension: Approx. 1.18" * 1.02"(30mm * 26mm)
Four Holes Panel Dimension: Approx. 4.13" * 3.42" (L * W)

Package Included：
1 * Four Hole Panel Base
1 * Dual USB Socket
1 * LED Voltmeter
1 * 12V Power Outlet
1 * ON-OFF Toggle Switch
4 * Mounting Screws
9 * Insulated Terminals
4 in 1 Design: Multifunctional switch panel comes with 1 x12v RV USB outlet, 1x LED digital display voltmeter, 1x 12V cigarette lighter outlet and 1x LED rocker toggle switch. Convenient for install and operate. Also detachable to replace other charger sockets or anything else that fits.
Dual USB Charger Socket: This 12V USB socket is built-in dual USB charging ports, two ports output: 5V / 2.1A & 2.1A (total 4.2A), will auto-detect your devices and simultaneously charging 2 devices at optimal speed!
Real-Time LED Voltmeter: This switch panels for trucks with large digital voltmeter display that shows 9-24V voltage, you can monitor the condition of the battery on your car or boat that if the voltage is under normal status. LED diplay makes you easy find at night & check connect situation.
All-round Protection: CE & ROHS certified. Featuring over current protection, over heat protection & over charge protection, Kohree waterproof car charger panel will automatically stop working when overloaded to prevent your devices from overheating & overcharging.
Wide Compatibility: This switch panel can be widely used for DC 9-24V car, marine boat, RV, truck and charge your cellphone, iPad, iPhone, iPod, GPS, digital camera, or any other device.