If you don't use a shoulder rest but are required to wear something that does not allow your violin to rest directly on you collar bone, this works great, it has just enough friction to stay in place.
The adhesive is really good straight out of the package but gets depleted quickly, washing it brings it a back slightly but nothing like it was original, but it is good enough, does not leave residue on the violin.
Further because the adhesive is in the middle of the pad if you don't contact with the center of the pad on your shoulder, for example: only on one edge for example, it can pop off the violin.