This is an improved runout sensor housing for the Elegoo Centauri Carbon that uses 2 PC4-M6 pneumatic fittings on either end so you can directly connect a boden tube to it.  You can benefit from this if you use an external dry box, or something like an Infinity Flow device that uses a boden tube and still want to use the runout sensor.  

With this new housing, you can now use the printer's sensor in the loop and keep from having failures due filament running out or changeover issues from external systems like the Infinity Flow or a dry box.

Housing is made to be near identical to the original so it will fit most designs for it, but it now has threaded holes to insert a PC4-M6 fitting on both ends.

— How to use — 

• Use a long 2mm allen tool to push into each side to make sure the filament will fit
• Install the pneumatic fittings on each side.  Make sure the fitting is straight and perpendicular to the hole before tightening
• Pull all the parts from the original runout housing, to include the bearing
• Put the sensor board in before the spring loaded tensioner
• Insert the bearing
• Insert the tensioner and spring
• Put cover on and install on printer.
• Push PTFE tubes into fittings
• Test to make sure filament moves smoothly through housing