This product is one of the best battery chargers and portable power units I have ever used! As my tests showed, it`s a great tool for jumpstarting a car and its compactness makes it easy to carry around in my car trunk. I no longer have to worry about being stranded on the side of the road with a dead battery. The only con I could find is that it can be a bit pricey compared to other jump starters in the market. Nevertheless, the Morningstar Corporation MeterBus Adapter UMC 1 is definitely worth every penny..