This category includes feed through wide belt sanders for the finishing of flat panel/sheet components for primarily the Woodworking Industry, but also some plastic and metal sheet applications. 1 head to 4 heads are the most common. Adding additional heads permits finer component finishing by placing higher grit belts on the 2nd, 3rd, and 4th heads to allow fine finish sanding with only 1 pass through the machine. There are basically 2 types of heads. Rollers tend to be more aggressive and are generally used for stock removal, while pads give a larger contact area and generally provide a better quality finish. A common configuration is a 2 head machine with 1 roller followed by 1 pad.