Using this car charger with built-in voltmeter our team found that it efficiently charges our devices without blowing up our car's fuse. The waterproof technology makes it perfect for outdoor trips, adding a sense of security amidst weather concerns .However, the display may not be as visible in bright sunlight. Overall, a small investment that provides great value. Keywords: Automotive, Charger, Waterproof, Voltmeter, Efficient, Display, Outdoor, Value..See full review