While installing an Infinity Flow S1 on my Ender 5 Max, I discovered that PFTE tubing must be present and secure for the entire filament path. My choices were to eliminate the runout sensor and run PFTE directly to the toolhead from the Infinity Flow, or make an adapter for a PFTE coupling.

I wanted to retain the runout sensor in the unlikely event of a complete runout, and this is what I came up with. Recommend use alongside my toolhead fitting adapter if you're using an Infinity Flow setup. 

1. Screw a PC4-M10 fitting into the socket.

2. Remove the screws from the filament runout sensor and store. 

3. Place the model over the runout sensor inlet, secure with two M3x25mm screws.

4. Insert PFTE tube as far as it will go.

Any filament should be fine for this model. Supports not necessary.