The Sunlight Supply Classic Grow Tent greenhouses are compsed of a light-tight and light weight material with highly reflective interior surface walls. Reinforced stitching in high wear areas and heavy duty zipper creating a rugged and durable grow environment. The internal exoskeleton that holds up your tent is comprised galvanized steel poles and unique quick connect molded plastic corners. Features: Quick Assembly Strong plastic molded corners: no bolts to lose Velcro tray bottom High and low lamp/power cord ports 10" duct ports Large for the biggest ID trays available Actual Sizes: #749900 - 52.7" x 34.4" x 79" #749905 - 40.2" x 40.2" x 79" #749910 - 56.8" x 56.8" x 79" #749915 - 112.8" x 56.8" x 79"