3.5" Diameter, .300 Wall Gravity Roller Conveyors are ideal for applications that require an economical, non-powered means for conveying material. This heavy duty conveyor is used for handling full pallets, drums, and containers. The 3-1/2" o.d. x .300 wall, high capacity rollers, and standard structural channel frames, are suitable for heavy loads, and the most abusive industrial applications around.