The Pack Off Stage Tool (POST) combines the functionality of a standard external casing packer with the operations of a stage tool all into one tool. This provides a mechanical barrier with the ability to split cement into separate stages as well.
The POST is unique in the fact that unlike the standard casing packer, the POST operates mechanically versus hydraulically, allowing some freedom during casing pump down
It also eliminates the need to land a plug to operate the tool, because you just need to drop the opening cone to inflate the packer portion of the POST
The rest of the tool operates like a standard hydraulic stage tool, providing the best of both worlds