Well, low tunnel is more accurate. I threw this together in less than 10 minutes from stuff I had on hand. An old bit of plastic film, a section of light weight wire mesh, and a couple of two by fours. "Built" it right on the front porch. It's a little over 4 feet long, and not quite 3 feet wide. The other day, it was in the low 30s outside and the temp inside got over 90 before I opened it up. Seems to do the trick!