This is our RV Car Boat Panel Dual USB Socket Charger+LED Voltmeter+12V Power Outlet 4 in 1.  This four-hole panel includes 2 USB charger socket (Output: DC 5V / 4.2A) + LED voltmeter (Display range: 6 - 24V) + 12V power outlet (Output: DC 12V) + ON-OFF Toggle Switch, they are interchangeable. You also can replace any port with additional USB outlets, or anything else that fits.

Features:

• SAFETY DRIVING: The LED voltmeter shows 9-24V voltage when driving which can remind you whether the voltage is at a normal level, ensure driving safety. The cigarette lighter socket Works with any standard cigarette lighter plug or lockable marine plug.
• 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.

Specifications:

• Type     Multifunction Panel
• Color     Black
• Material     ABS
• USB Output     DC 5V / 4.2A
• Power Outlet     DC 12V
• Voltmeter Display Range     0 - 24V
• Toggle Switch     20A 12V DC
• USB socket dimension     Approx. 1.1 x 1.57inch (Screw Diameter * Height)
•  Voltmeter socket dimension     Approx. 1.1 x 0.6inch (Screw Diameter * Height)
• Power socket dimension     Approx.1.1 x 1.57inch(Screw Diameter * Height)
• ON-OFF Toggle Switch     Approx. 1.1 x 0.7inch  (Screw Diameter * Height)
• Four hole panel dimension     Approx. 4.1 x 3.4 x 0.19inch (L * W * H)

Package Includes:

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