This is a newer drop that can snap onto the input port of the printhead, and has a bevel on the input side of the elbow to ease install of the PTFE tubing. Note its intended to be a firm grip on the process so the tube doesn't easily come back out.

Note this drop also has a slit on one side that allows you to unsnap it even when filament is loaded or for when you are needing to load without the elbow for whatever reason. Some have needed to add a few percent of scale to it, but not everyone for some reason. It may be the nuances of printer config or material.