Tells FieldCAD which region to evaluate a Solid or field in: the combined extent of the listed bounding boxes. The shape itself is not changed; only where it is drawn, meshed and measured. Use it to give an endless shape, such as a half-space or a loft, a finite extent. With no boxes listed the input's own bounds are kept.
The Solid or field to bound; it passes through unchanged.
Values the block gives besides its output. The editor lists them under Properties, and an input can read one by reference.