2 in 1 Dual USB Port Phone Charger Red Digital Voltmeter Car Motorcycle Truck

Features
Universal voltage meter and USB charger for motorcycles, cars, buses, trucks, RVs, boats and yachts.
Can be used to charge GPS, cell phone, MP3 or interphone.
Dual USB port and maximum 2.1A current output.
With High-Tech IC, decrease charging current when the battery is nearly full
With reverse polarity protection
With overload protection
Wide operating voltage range, compatible to DC 12V and DC24V, up to DC 30V
High refresh frequency
Low power consumption
Soft red light
Replaceable 5A fuse tube.
With 60cm power cable.
Round shape, easy to drill a hole to install
Spec
Operating Voltage: DC 8V – DC 30V
Output Voltage: DC5V
Output Current: 2.1A and 1A
Voltmeter Operating Current: under 10mA
Voltmeter Refresh Frequency: 10 times per second
Led Color: red
Display Dimension: about 21.2*8.6mm
Dimension: about Ø36.8*50.5mm
Power Cable Length: about 60cm
Mounting Hole Dimension: about 28.8mm
Package Include
Dual USB charger & Voltage Meter *1
Fused Cable* 1
Tips
The power lines are with 6.3mm connectors, you can change the power lines yourself.
If the connector plug is not suitable, you can remove the plug and connect to the circuit directly.
To install it, you need to drill a hole which diameter is about 28.8mm.
Connect the red line to the ACC terminal on car or ignition lock “ON” terminal on motorcycle. Connect the black line to the ground terminal.
Do not connect it directly to the battery on car or motorcycle. If you want to, use a switch to control the charger.