This Feature may have different enhancements or upgrades, particularly in an installation designed to contain prisoners long-term. For additional Feature ranks, the cells can have the following options:
Impervious on the Toughness of the cells.
“Punishment” cells (an Affliction effect at the installation’s power level).
“Sleeper” cells (an Affliction effect at the installation’s power level that keeps prisoners incapacitated).
D20 Hero SRD Installations Article- http://www.d20herosrd.com/7-gadgets-gear/installations