Basically just a triangular 1x2 frame covered on all sides with lattice. The back side that would be pointed in doesn't go all the way up so you can get to the legs on the canopy. Stretch out the canopy then set it on top of four of the corner pieces and lash the legs of the canopy to each. Then just hang signs etc on the corner posts for weight. Keeps the wind from tossing the canopy all over the place.