When you go to add another generator to your system, the bare minimum recommended to be ordered is:
1. Generator (comes with the power and USB cable)
2. Boost (unless you have spares or plan on not using one)
3. White (BN) remote (if you plan on using this generator in remote mode)
If you started with a kit, you already have the contact cables necessary to use the generator in contact mode.
If you do not yet have a USB hub, but have a spare USB port, then you do not have to yet worry about this. However, suggest that if you plan to expand further, that you think about a powered USB hub down the road.
For more details, please check the link: