What are extras?----
Extras are an addition you can put on your configurations, to help you ship in many ways, quick easy repairing, help you out in battles even jumping to your home maps instantly. There are many types of Extras you can use, repair bots, jump chips, cloaking chips, smartbombs, many many more.
To find these extras you can go to your Hanger:
Then clicking on Extras:
You can have a look at this page for a detailed overview of the all the CPU and their functions. Extra
Below is the picture of all the CPUs you can buy, but remember you can only have a limited amount on your configurations.