Another basic cutting spline with fences, double-sided to compensate for the different normals shading depending on which direction the spline is drawn out from its origin - so a standard two-sided cutting can be made from two of these splines extruded in opposite directions and the colours should match. The screenshot shows how different the shades can be depending on the direction in which the spline is drawn, as well as displaying the profile,intended to help when a greater height and distance needs to be filled than a simpler, smaller cutting spline can handle.
The texture matches other assets sharing the MGGI suffix.
You will find further details and examples of their use in my 'Modular Landscape Kit' thread in the Freeware Anouncements section of the Trainz forum.