The steel supports are galvanized. I suspect some minor rusting where I welded it together.
The top material is light weight plastic sheets. Some folks call them fibreglass sheets. The proper term is "Polycarbonate" sheets. Same stuff they put on shed roofs, sun rooms and green houses. re: http://www.iwilltry.org/w/images/thu...uth_roof_6.jpg
If wondering, I bought these 2ft wide by 8ft long sheets (which I cut down to 4 ft lengths using a hand grinder) at my local lumber store. They had them on the shelf and "on sale". But, most lumber stores have them as special order items. Instead of buying high cost special screws, I used normal flat washers, screws and put some clear silicone under each washer. And, on the exposed screw head. Thus, sealing its contact and slowing down its natural rust as well.
Each panel (3 panels in total) can be lifted with one hand. Approx 5-8 lbs each panel. The 3 x vertical poles are telescopic and support weight of the panels. NO weight on the slide's outer edge. And best of all, the weight of the poles hold the light weight panels down - in case a strong wind gets under these panels. I picked dark green color because the panels were avaialble and on sale. Some folks might pick a different color.
Hope this helps in your research....