This is the Dual Pressure MKIII CO2 Regulator - you'll find the single pressure regulator.
Need to set two different CO2 pressures for different beers on tap? Then you'll need two regulators to do it properly. With this MKIII Dual Pressure Regulator you'll be able to screw it into your CO2 bottle and fire away with two different pressures. No need to removing the High Pressure gauge off one regulator, buying an attachment and joining the two together.
From: Kegland
Note: CO2 bottle not included.