Good quality - warm attack, long lasting, but grip could be better.
I use these to play mandolin, octave mandolin and guitar, I've found out I really like to use the same kind of thick pick across different instruments for better control and having a standard "pick feel".
Mandolins need a sturdy material and the standard pick plastic wears out super quick, but celluloid picks like these are much longer lasting, so it's a really good choice for mandolin players particularly. It also sounds better to my ears, with a brigter attack than standard plastic.
Grip could be better though and I always score notches into all picks with something sharp. It's an easy fix, but it leaves something to be desired.