The
Aperture Science Handheld Portal Device, often simply referred to as the
Portal Gun, or its acronym, "
ASHPD", is an experimental tool used to create two
portals through which objects can pass. The central piece of the "Portal project", Tier 3 of the
three-tier program created by
Aperture Science's CEO
Cave Johnson on his deathbed in
1976, it is used within the
Enrichment Center's Test Chambers, as the Test Subjects' primary tool to complete each chamber.
