I just made my own out of a cast-off gallon plastic garden sprayer. For an MB, found an old cap, drilled a hole through it. Removed the wand assembly and used the ferrule that secured it as a nut to fasten the cap to the control handle. It's a bit more difficult to use than the purpose built ones, but the price was right.

You don't need the gauge, really. Just start with a dozen strokes and see what kind of flow you get- increase as needed ( within reason)

However you make or buy it, you will kick yourself for waiting so long to use one.

Army- we don't have Gunson's here. Good solution- 26 pounds? ouch...

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