Abstract: A baseball backstop or similar structure, such as dog run, fence section, etc., is constructed of panel sections uniquely connected together so the entire structure is foldable for shipment to the erection site. The panel sections are each made up of steel tubing, forming a frame, and of steel chain link fence fabric covering the frame. Adjoining frames are hingedly connected by sleeves of larger diameter steel tubing rigidly secured to the frame of one of the adjoining panel sections, as by welding, and closely but freely encircling a frame member of the other of the adjoining panel section. The chain link fence fabric of the one panel section is secured at one of its sides to the frame of that section and at its opposite side to the said frame member of the other section. Set screws in the sleeves provide rigidity for the structure after erection.