This is a tooth paste key that will stay wound. It will accommodate a tube up to 53mm wide. It works very well.

• UPDATE 7/5/15 - I just uploaded a wider version (ver 5.1) to accommodate wider tubes. I have also rounded some of the edges to prevent splitting or tearing the tube and to pretty it up a bit. The print stats will stay the same.

Printed at .2mm, 3 walls, 60% infill, no support. It seems more than sturdy enough and took about an hour and a half to print on my Makerbot Replicator 2x.