A good device, but hardly, with such a low battery capacity, it will be able to start a frozen engine. Works great as a power bank for mobile gadgets Has pros: Multifunctionality. Made with high quality. Convenient storage case Has cons: Clueless instruction. It can't turn on the device. Nothing is said about the role of the "on-off" switch, which is essentially the main switch, but is labeled "switch" in the drawing of the outside of the device. The multifunction button works very indistinctly. Practically nothing is said about how to switch the power supply voltage of laptops "12-16-19 Volts".