Sometimes our house will be blackout, at this time there is no router power supply, we can not access to internet, but if we have this product, we can solve this puzzle. This is a boost USB cable, 5V power supply can be boosted to 12V, then if used with a mobile power charger, it can be a normal power supply to the router. Simple to use but practical products. And we also supply 5v to 9V cable for your project. You can choose any one you want.