I have that same roll cage on my MT-2 and it didn't add much weight to it and it is very solid pretty easy install as well not sure exactly what it is made of but it is very lightweight but sturdy. Also you more then likely will need to cut a bigger opening at the back of the body in order for it to fit on over the cage but that isn't that big of a deal. All in all I say it is a pretty good buy.

Here is a link to a picture of my truck you can kinda see the cage when you look at the back. I painted the cage silver so it looked better with my custom body.

[link]http://trucido83.deviantart.com/art/My-MT-2-56406199[/link]