Groove Mount Bowden Adaptor (4mm OD Tubing)

This is a neat little solution for quickly and easily converting a direct extruder that would normally accept a groovemount hotend into a bowden extruder. Simply mounts in like a HotEnd, but instead accepts our PTFE tubing securely in an embedded bowden coupler.
 
Quite a bit nicer than forcibly screwing a threaded bowden coupler into a printed hole, and allows you to use the existing plethora of excellent direct extruders available in a bowden setup.
 
If you're designing your own bowden extruder you might consider using this to secure your tubing instead of a screw in coupler.