Geipel thumb pick quickly became my favorite. I have tried a lot of thump picks and only a handful fits nicely (snug, but not blue finger tight) and produces excellent sound. I use it with a 5-string bluegrass banjo and occasionally with an acoustic guitar. If you need to tighten or loosen them a bit, you can easily do so as they are pretty flexible. I've been using mine for a little bit over a mont now (2-3h a day) and it still looks pretty new. Already ordered some more of these.