A replacement for the push to connect M10 connector on your Creality hot end. This version has an inner diameter of 4mm, allowing you to push the bowden tube all the way through. This allows you to tighten the bowden tube directly against the hot end, instead of using a separate section of PTFE tube (this is how the Creality hot ends are normally constructed). This type if compression coupler does not loosen over time, as compared to a standard push-to-connect fitting which will slowly dig into the tube and loosen over time.

Requires tightening nut from: https://www.thingiverse.com/thing:3360380