Docking Field

Docking Field is a barrier that prevents NPCs and monsters from passing through. Player can walk through it normally.

This is helpful for preventing the crew from jumping out of the airlock.

Docking Field has a wiring that sends ON signal if someone touches the barrier.

About tooltip
Despite what the tooltip claims, Docking Field is not considered a solid wall (for the purposes of "is the room enclosed?" checks), which matters if you are using "Atmospheric Mode" (which you can enable/disable in SAIL). If this mode is enabled, then oxygen/gravity are only added in rooms that are fully enclosed. If Atmospheric Mode is disabled, you always have oxygen/gravity if you are in front of background blocks, and the room won't be checked at all.