Rinnai water heater cold water inlet filter tool

Went to drain my Rinnai water heater and found that you are instructed to remove the cold water inlet filter, which has a pretty unique design that could be damaged trying to install with pliers. Maybe the heaters came with the plastic tool for removal/installation but I don't have it, and the only aftermarket option I found was an over-engineered metal socket for $30.

Including two version, one has knob geometry to use by hand, the other has a ¾" hex geometry to be driven by a socket wrench. I found that the knob was sufficient to fully tighten, just make sure you start threading it by hand to avoid cross threading like I did at first.