I have one out of wood, sorry no pic, for the sides frame just like you would frame a wall - 2x4 16" o.c. - 6' high. Then run 5/4" decking boards about 6" apart for the sides - run the decking boards along the inside of the trap so hog can't push the decking off the 2x4. Front is a drop door 3/4" plywood. I tie the sides together in each corner w/stout rope, 3 places in each corner - bottom/middle/top. It is heavy so tote it in in pieces - then tie together. Still need to tie trap to a tree so a big hog will not flip over. Have used for 3 yrs and so far - no problems.