The 2nd Stage In-Line Adjusting Tool is used for fine tuning regulator 2nd stages which have an adjustable air inlet orifice that requires either either a flat blade or hex key tool to make the adjustment. Our Second Stage In-Line Adjusting Tool has BOTH an 0.032 inch flat blade, screwdriver-like adjusting tip, which fits most slotted regulator orifices and also a 5mm hex key adjusting tip plus a built-in IP gauge to verify the inter-stage pressure. To change between the two tips, the tool is easily reconfigured. To see how to reverse the tool to swap the adjusting tips, please watch the Youtube demonstration VIDEO for Second Stage In-Line Adjusting Tool.