Parallel roller has a high wear resistance, low coefficient of friction, not easy to wear belts; excellent self-lubricating, no oiling required, using well in adverse conditions; anti-static, anti-oxidizing, anti-aging, anti-acid , alkali and corrosive organic solvents; to withstand repeated shocks, vibration; the range of ambient temperature: -40 ℃ -90 ℃; excellent mechanical properties, light weight, easy installation, no maintenance; smooth operation and long-life usage.