Roller tables have multiple straight rollers and are commonly used for feeding flat-bottomed sheets, planks, and bars into or out of machinery in machine shops, woodshops, and other fabrication facilities. They provide more stability and have more surface area for supporting conveyed materials than single-roller stands. They can be used with items that are wider than the roller width, and they are also suitable for conveying items that would fall into the spaces between ball transfers on a ball transfer stand. Longer tables may be used as temporary extensions in conveyor lines. The rollers only allow items to move forward and backward on the table. The height of the table can be adjusted to help ensure the materials are appropriately aligned for the intended tool or process.