Virtually unbreakable 4 mm twin-wall polycarbonate roof panels block up to 99.9% of UV rays and diffuse sun light eliminating the risk of plant burn and shade areas Crystal clear polycarbonate side panels provide 90% light transmission Rust resistant aluminum frame with 48 sq. feet of growing space Includes adjustable roof vent, rain gutters, lockable door handle with magnetic door catch and a galvanized steel base for structural support 5 year limited warranty and US based customer support The Nature Series works with Palram' s line of hobby greenhouse accessories to maximize space and a more productive growing season