Simply put, roller conveyors are a form of conveyor belt that utilizes rollers - evenly-spaced rotating cylinders - to allow objects to skate across its surface. They move material from one place to another destination, and often leverage gravity or implement small motors to do so. The transported material must have a rigid riding surface that is supported by a minimum of three of the rollers. http://www.wxhq-group.com/roller-conveyor/