I was looking to buy some more of these units and I noticed the poor review and wanted to add my perspective. We bought 3 of these units about 5 years ago. They still look "new" We are SERIOUS gardeners with 3, 40'x40' gardens. We raise everything from seeds, starting in Feb/Mar, and then transplant and put the pots in these cold frames. While they are not [$] greenhouses, they work just as good. They hold 3-4 flats each and are easy to open, close and remove/replace the lids. We mount them to 2x6 boards on the patio so that they will not blow away during a spring storm. By June (we are in WI) the tomatoes, etc. are more than 1' tall and very strong. I agree they would not do well in the winter or in the snow. Highly recommended.
I ordered this greenhouse with the intent of placing it outside during the winter. However, the material it is constructed from is thin, poor quality plastic -- I have gotten take-out food in sturdier containers. I doubt it would stand up to wind, rain, or animals. This item is not worth the price charged.