Nature's Premium Greenhouse Kit is constructed with 4mm polycarbonate panels and a powder-coated aluminum frame that will last for years to come. It is ideal for protecting seedlings and young plants from late season frosts and getting those seeds and young plants ready for planting. Early planting means a stronger and more mature plant to start the growing season. These greenhouses measure almost 2.1m wide and have a roomy headroom of 2.1m. The door for this greenhouse is a hinged, aluminum framed Dutch style door. Not a sliding type. And window roof vents provide ventilation for those hot days when your plants need it the most. Gutters and Downspouts are included for collecting rain water for your plants as well. Stable enough that no base is needed for this greenhouse. Another big plus of the Nature's Premium Hobby Greenhouse is that it is expandable. So if you need more room, it can be enlarged it in the future. Expansion kits are available that can actually add length to your greenhouse.