Greenhouse frame has pre-drilled holes ready for stakes or for mounting on a concrete slab, 4x4's, railroad ties or pillars.Frame is made of resin products that are maintenance free! 2 hinged doors -- easier to use and more durable than sliders (5' 7") UV coated Polycarbonate (4 mm) glazing for better sun protection, light diffusion, heat insulation and strength and safety. The innovative PUSH & FIT connectors enable you to snap it together yourself and allows it to be expanded later. Every Hobby Greenhouse comes with a Rear Louvre Window and an Auto Opener for each Roof Vent. This Greenhouse has 5 Roof Vents. Sturdy and durable -- can withstand winds of up to 80 mph and support a snow load of 1100 lbs. 7 year warranty against manufacturer's defects