Silverstein OmniPatch Black

Saying that because, surprisingly enough, it's not the case with all mouthpiece patches. They stay in place - not the case with all mouthpiece patches. If you put them on in slightly the wrong place (easily done) you can peel them off and put them on again - not the case with all mouthpiece patches. They retain their consistency over time - not the case with all mouthpiece patches. They don't pick up scale deposits (getting hard and dirty) - not the case with all mouthpiece patches.

So they also have a groove and are thick(ish) and soft. Not everybody likes those attributes. For myself I find the groove a helpful reminder for locating position on the mouthpiece but it doesn't lock you in. I also prefer a soft and thickish patch - too thin sets my teeth on edge.

As so often with Silverstein more expensive than the competition but well worth it.