The Tube primitive creates a tube shaped Vectron object (figure 1).
Figure 1: The Tube Vectron object with the Round Base parameter set to 1
Width - Determines the width of the tube.
Height - Determines the height of the tube.
Depth - Determines the depth of the tube.
Thickness - Determines the thickness of the tube's sides
Round Base - Rounds the vertical edges without rounding the horizontal edges. A value of 1 will make the tube completely round.
Round - Rounds all edges equally.