This cable allows a standard 5V USB power bank to be able to power 12V devices such as modems, routers and Wi-Fi devices. This cable can be connected directly to a 5V USB power bank or port. The internal electronics will step up the voltage to 12V on the DC output plug. With this cable, you can connect your power bank to a router. Thus, when power is cut, you can use your power bank to supply your router! If the 12V equipment cycles on and off, it means you are overloading the cable or you are powering from a low power USB port. This cable also can be used to CCTV Camera or emergency light if it has a DC charging port. Please note that in order to achieve the 12V/1A boost, the cable needs to be plugged into a USB 5V/2.4A port. This means that the cable needs to be plugged into a fast charging usb port. It is advisable to check that your power bank can output this high amperage as most power banks can only output up to 5V/2A. I would recommend to purchase a USB A to USB C adapter as well, if you are unsure. You can then plug the input side of the cable into a USB C port instead of a USB A port, as any USB C port will provide enough current to the cable. To those saying that the cable doesn't achieve the boost, it does but make sure you're router/ONT has an input voltage of 12V/0.5A or 12V/1A otherwise the current required to the router is too excessive meaning the boost won't be achieved. 12V/1.5A routers won't work, don't buy this cable in that case. What's in the box 1 x Voltage Converter USB 5V to 12V (Power Bank to Wi-Fi Router)