21st Century Cejilla for 6 string classical / flamenco guitar
[cejilla-6]

Likes: I can slide it up above the nut to use later; works well for songs with key changes. Solid contact with strings. Good construction.
Dislikes (minor): the yellow string can slip out of the grooves, when I move it as described above, so I have to take a few seconds to put string back in place. I'm thinking of making the grooves a little deeper and/or loosely clamping one of the strings.
I'd buy another one - they're nice.