- Level: (3D, elevation, and section views only) specifies the reference level for the duct.
- Diameter: specifies the diameter for a round duct section. Transitions are automatically added to establish connections in the system. If connections cannot be maintained, a warning message appears.
- Offset: Specifies the vertical elevation of the duct relative to the current level. You can enter an offset value or select from a list of remembered offset values.