... 20'1.Easy moveCoz it is just like container of its size,shape,the container house could be moved more easily,so ... accordingly.3.20' or 40' containerFor material,we could follow your opinion,but the main material is galvanized steel,EPS,rock wool ... size,it is also flexible,smaller or bigger than standard container more or less.4.Assembled or welding typeAssembled and welding ...