SFS Standard Enhanced Shell Feat 5

Source Galactic Ancestries pg. 102
Prerequisites Armored Shell
You've enhanced your exoskeleton with cybernetics or biotech to make it even sturdier. The item bonus to AC from your exoskeleton increases to +4. You can use the Install Upgrade activity to install armor upgrades into your exoskeleton; your exoskeleton has two upgrade slots.

Traits

Copaxi:A creature with this trait is a member of the copaxi ancestry. They are a colony of genetically identical polyps with a humanoid form and coral-like exoskeleton who can manipulate gravity. An ability with this trait can be used or selected only by copaxis.