Abstract: A sheathing for extending members having either a rectangular cross section or a circular cross section is formed of sheathing sections wherein the sheathing sections have two positions. In a first substantially flat position the sheathing sections are convenient to stack and when stacked the surfaces of adjacent stacked sheathing sections are substantially in contact with each other. In a second folded position the sheathing sections define an enclosed hollow space for disposing an extending member therein and surrounding the extending member to protect vehicles or other objects striking the extending member. Articulating hinges are provided for transposing the sheathing sections from one of these positions to the other. The sheathing sections are provided with dove tailing interengagement for joining sections of the sheathing to each other. Inserts brace the walls of the sheathing against extending members inside the space defined by joined sections.