Sonic Tools - Wedge Utility Set - 5 Pieces pressure washer individual upgrade kits Use the 24mm (or 1")

Use the 24mm (or 1") wrench to install the coupler by pushing against the other wrench

What you really want is a complete sprayer/wand/foam cannon upgrade kit

If there's a way to do something better

Add a few dots and polish on Speed 4 on your RUPES polisher

Sonic Tools - Wedge Utility Set - 5 Pieces pressure washer individual upgrade kits Use the 24mm (or 1")These are the tools I've decided to use at OGHQ, they have a nice quality to them with good ergonomics. They aren't intended to replace everything but there is a great variety of tools offered here. For the price you cannot beat them vs something that's 2x or 3x the cost like Snap On.