Systems Trading EG45812 Backyard Hobby Greenhouse, Green, 8 By 12 Feet (Discontinued by Manufacturer) Greenhouse with automatic roof vent, double doors and side shelves 4 mm twin polycarbonate thermoplastic for optimal durability, insulation Hinged double doors for easy access; side vents and automatic roof-vent for airflow Shelves on 2 walls for starts and shorter plants; 100 percent UV protection protects skin Heavy gauge aluminum frame for durability; measures 12 by 8 by 7-1/2 feet (l x w x h)