Volt Meter
thingiverse
https://www.banggood.com/5Pcs-Geekcreit-Yellow-LED-0_28-Inch-2_6V-30V-Mini-Digital-Volt-Meter-Voltage-Tester-Voltmeter-p-980045.html?cur_warehouse=CN Yellow, but other colours available. Use hot glue to hold the electronics into the 3D printed part. Use Superglue to seal and make waterproof. Use superglue to attach the back parts.
Download Model from thingiverse
With this file you will be able to print Volt Meter with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Volt Meter.