Roller conveyors are especially beneficial and efficient when the handled product are parcels, totes or suitable geometrical shaped. They can be either driven or gravity, depending on its usage. Roller conveyors without motors carry products downward with certain slope with gravity force. Driven roller conveyors can carry products at points without inclination. Although it is very small, the rubber coating of the rolls enables the products to be carried up to 3-4 degrees sloped environments. It also offers buffering compared to belt conveyors. However, there is no safe and controlled transportation at the points where the gravity rollers are used.