Foremost, I encourage you to buy from me for £3.95 each, you will support my work and you will be assured that the quality of the component will be printed in the correct material with the correct elastic properties.
I cannot be responsible for any defects relating to you printing this widget for yourself.
Note : It will not work if printed in PLA or any other rigid plastic.
The only material I recommend is Filaflex 95A from Recreus.
I allow people to 3D print this for themselves, or for others for free (non-commercial). I have designed and gifted the CAD model freely for this purpose only.
The only authorised repository for this model is held on Thingiverse and it is licensed under the Creative Commons – Attribution – Non-Commercial – No Derivatives license. This design was published on 3rd of July 2020 and is established as prior art. Any subsequent patent application based on this or similar derivatives will be invalid.
Click to take me to Thingiverse where you can download the authorised model