an open hole packer uses mandrel expansion and a surrounding sealing element that can optionally have a swelling feature and further a seal enhancing feature of a ring with an internal taper to match an undercut on the mandrel exterior . as a swage progresses to the taper at the transition between the ring and the extending flat fingers , the fingers get plastically deformed in an outward radial direction to push out the sealing element . shrinkage of the mandrel axially due to radial expansion brings a ring on the mandrel outer surface under the fingers to act as a support for the fingers against the seal which is pushed against the open hole . mirror image orientations are envisioned to aid in retaining pressure differentials in opposed directions . another external mandrel ring extends into the seal to keep its position during differential pressure loading .