These regulators are having wider outlets pressure range. The outlet pressure can be easily adjusted by rotating the knob of spring adjusting screw. By rotating the knob anticlockwise the outlet pressure is reduced & by rotating it clockwise the outlet pressure is increased. R-2101 & R-2111 are mainly used for gas cutting or welding purpose. These regulators have built in safety relief valve and flow control needle valve at the outlet. R-2202 is mainly used as adjustable pressure regulator for LPG / Natural Gas in canteen restaurants & for small furnaces. R-2105 is suitable for high pressure application.