Wide Compatibility: Fits for Car, Boat, Marine, ATV, RV, Motorcycle and other 12-24V Vehicles. Use for mobile phones, Tablet, GPS, digital cameras, PDAs etc.
Safety Driving: Built-in LED digital display voltage monitor, shows the accurate voltage status of device in real-time, prevent your motorcycle or car from starting hard, off and on intermittently and the headlights not enough bright cause by too low battery voltage, or prevent your motorcycle or car from engine instability or horns stopping working cause by too high battery voltage.
Safety Protection: It's certified by CE & ROHS with Overload, Over-current and Short Circuit Protection to ensure charging safety, meanwhile, built-in converse connection protection that ensures the circuit won't be burnt out if wrong wiring.
Dual USB Fast Charger: Dual USB interface design with single output of 2.1A (max total output of 4.2A), it quickly charges for most smartphones, tablets, GPS, digital camera, PSP/MP3/MP4 and other USB-devices.
Please note: The voltage reading will be visible only by connecting to the battery and the voltage also can be read when the cover is engaged.
Cllena Dual Port USB Charger Socket Power Outlet 2.1A & 2.1A with LED Voltmeter for Car Boat Marine Motorcycle Mobile (Green) - B072NC6W1Q