The wire arches need to be put into casings on the plastic. It's difficult to do and one of the casings had a hole in it which allowed the arch to poke out. Also the very first one I opened, I purchased four, there was a 4" rip in the plastic that I had to tape.

There should be extra plastic sheeting all the way around so you can put bricks or other weights on  it so it doesn't blow away in the wind.