were do i install circuit boards? im confused

[rootsector]

im playing ksp and i cant seem to find were i use the circuit boards at ?

[maru]

Kerbal Engineer Redux career mode requires the circuit board part to be able to access the Engineer windows in flight.

[Vengarov]

If installing 'Kerbal Engineer Redux' circuit boards is not desired there is an option to switch between 'Career' and 'Partless'.

[rootsector]

ok thank you