HP "Probe Tip Covers".
Original design by Thilo, can be found on Twitter here:
https://twitter.com/thilographie\_de
They fit the following HP models:
Update
Found they don't fit inside the case when attached to probe, will look into doing a v2 at a later point to fix that. For now you could sand the sides off from one side to have them sit flush against each other
Update 2
Re-oriented model to stand up vertically, just for ease of use in your slicer :)
The author marked this model as their own original creation. Imported from Thingiverse.