Abstract: The present invention is a portable structure used for exhibition or sports (batting cage) applications including an expansion section with a plurality of expansion segments, each of which is self-contained. Each expansion segment is bounded by an upright member onto which an articulating arm is attached adjacent the tope and bottom. Each articulating arm bends at an elbow and folds flat against the upright members when each expansion segment is extended, the articulating arms straighten at the elbow and pivot in a scissor-type motion with respect to the upright members until the articulating arms are fully extended substantially straight. The expansion segments roll on rollers removably affixed to the upright members. The portable structure includes three positions, a transport position wherein large wheels or skids are suppled for easy manipulation of the device, an expansion segment wherein the expansion segments are extended or collapsed using smaller wheels.