Gravity Roller Conveyors are built on slight inclined. Since there conveying power is simply the force of Gravity. The inclination depends upon the type of material that is being used. When the material is placed on the conveyor, the roller revolve, thus moving the material in the direction of incline. 

Powerised Roller Conveyors are used to carry load at controlled speed. Roll to Roll chain driven live roller conveyor are used where dirt, oil, grease and other contaminations are present. The driving chain or chains are at ends of the rollers and are shielded