The parallel link kit uses cables specifically for the Honda EU70i generator. These cables are designed to link two EU70i generators together to get as much as double the output of a single unit. With a 63amp outlet you can power larger fixtures or longer cable runs than when using a single Honda 7kw generator.
This gives you extra power when you need it most, without having to hire a larger, heavier generator.
Please note that you can only parallel link two identical units together.