To be honest, this thing is used by the galvanized sheet material to do, so which do are almost the same, mainly a price and thickness of the problem, but it depends on what you do this is what to use, if it is a household or restaurant to do the smoke pipe, then casually on the side of the road to find a reasonably priced on it, but if it is the use of ventilation and cooling and ventilation equipment, then, strong Thai electromechanical can help you design! The first thing you need to do is to find a way to make sure that you have the right equipment.