Rion Hobby Gardener 2 Twin Wall Greenhouse, 8' x 16' Virtually unbreakable 4 mm thick twin-wall polycarbonate roof panels and 6 mm twin-wall side panels are 100% UV protected and high impact resistant Heavy-Duty resin frame improves insulation and creates extra durability for many years to come Maximum safety - no glass to shatter or break Hinged French doors for easy access and additional ventilation when open Included roof vent helps you maintain heat and humidity in your greenhouse as needed