FXC Four Holes Panel Base: Includes Dual USB Socket + Voltmeter + 12V Power Outlet + Toggle Switch. USB socket output: DC 5V 2.1A/ 2.1A, power outlet: DC 12V, Voltmeter display range: 6 – 24V.
Wide Compatibility: Widely used for 6-24V car, truck, Motorcycle, RV, ATV, boat, Camper Vehicles, etc. The USB socket port fits for charging any 6-24V devices and charges fast for iPhone, HTC, Galaxy, Blackberry, MP3 Players, Digital Cameras, PDAs, and Mobile Phones. LED digital display looks cool, especially in dark.
Small size and excellent performance. Easy to install and convenient to use.
Over- Charge Protection: CE & ROHS certified, display the current detected by the intelligent circuitry while charging. Intelligent circuit design protects against excessive current, overheating, and overcharging. Ensure the charging safety.
About the switch hole, it could be used for a cigarette, cannot be used to light cigarettes. If you don’t need the switch for a while, so enjoy it depend on what you would like it to been. It has two different uses.

Product description:
Color:Voltmeter + SOCKET + Switch + Power Outlet-Black+Blue
LiDiVi Dual USB Socket Charger 2.1A + LED Voltmeter + 12V Power Outlet+ ON-OFF Toggle Switch, Four Functions panel for Car Boat Marine RV Truck Camper Vehicle (Blue)

Material: ABS
Color: Black & Blue
Weight: 150g
USB socket output: Dual DC 5V / 2.1A
Power outlet: DC 12V
Voltmeter display range: 6 – 24V.
Voltmeter socket dimension: Approx. 28 * 16mm (Screw Diameter * Height)
Power socket dimension: Approx. 29 * 40mm (Screw Diameter * Height)
ON-OFF Toggle Switch: Approx. 29 * 18mm (Screw Diameter * Height)
USB socket dimension: Approx. 29 * 40mm (Screw Diameter * Height)
Four hole panel dimension: Approx. 104 * 87 * 5mm (L * W * H)

Package Include:
1 x Red Digital Voltmeter
1 x 12V Cigarette Socket
1 x Double USB Power Socket
1 x ON-OFF Toggle Switch
1 x Four Holes Panel
4 x Stainless Steel Screw
9 x Blue Terminal