I bought a couple more bells that I might try, but I'm unsure.
the first one is like the one I'm already wearing. it has the downside that the shiny coating wears off with time and that even affects the sound (although it's doing well for now after I replaced it in January)
the second one is a bit too small, but I like it because it's black, I know that's the color my Miss prefers for everything, and since it is attached to my locked collar, that feels appropriate. it's not a requirement though, she has given me freedom to choose myself.
the last one has a kinda dull appearance, but it doesn't look bad. the sound is quite nice too