The MKS Instruments 1559 elastomer-sealed Mass Flow Controller is designed for general purpose mass flow control applications covering the range from 20 slm (42.5 cfh) to 200 slm (425 cfh). The 1559's unique control valve eliminates oscillation and offers better response time as compared to other flow controllers. This feature is possible through the use of a "balanced force" valve design that automatically neutralizes line pressure-induced imbalances within the control valve. The 1559A High Flow Mass Flow Controller's accuracy is ±1% of Full Scale.