This .NET class wraps the AcGeBoundBlock3d ObjectARX class. 

This class provides spatial dimensional bounding volume implementation. 

Bounding blocks may exist in two forms: as an ordinary coordinate-aligned bounding box and as a parallelepiped.

Autodesk.AutoCAD.Geometry.Entity3d
    Autodesk.AutoCAD.Geometry.BoundBlock3d

Public sealed Class BoundBlock3d
Inherits Entity3d

public sealed class BoundBlock3d : Entity3d;