Pressor field

A pressor field was a ship generated energy wave that covered a vessel which protected it from attack. Despite this, it can be overwhelmed.

Generation 1 cartoon
A Quintesson cruiser in its attempt to locate a Quintesson Journal was uncovered by Superion whose power would have destroyed the ship. In order to protect themselves, the Quintessons activated a pressor field which held back the giant Autobot until he fired his shoulder cannon that nullified the field.