Large Space Size: 4.5 x 2 x 2 m/14.8 x 6.6 x 6.6 ft. Our tunnel greenhouse has a large storage space with one door and 8 mesh windows to increase air flow for plants to thrive.Galvanized Hoops This high tunnel greenhouse uses upgraded heavy-duty hoops with a 0.02" thickness and 0.8" diameter. The galvanized coating is rust-proof for long-term use. Galvanized Hoops This high tunnel greenhouse uses upgraded heavy-duty hoops with a 0.02" thickness and 0.8" diameter. The galvanized coating is rust-proof for long-term use.