1.Silver Axis 2.satisfy flexble moving 3.Prevent rain and dust 4.low noise and high loading capacity Tube diameter Axle diameter Tube length wall thickness Tube material Surface tretment Φ20Φ6 50-4001.0 carbon steelstainless steelPVC pipeAluminum pipe zinc-platedchromeplateNickel-platedRubber-covered Φ25Φ8 50-6001.0 carbon steelstainless steelPVC pipeAluminum pipe zinc-platedchromeplateNickel- ...