These thumbpicks are great, I'm really hooked on them.
Banjo player and inventor Bill Stokes has designed a thumbpick that closely replicates the tortoise shell tone. (tortoise shell picks are illegal) Years ago, picks were made from real tortoise shell but that practice has been against the law for many years so entrepreneurs and designers have been trying their best to come up with a suitable replacement. The trick has been to come up with a thumbpick that provides the tone of the old tortoise shell picks and keep the costs down too.
This is the best one I've seen by far. I highly recommend them.
Bill Stokes just agreed to make left handed tortoise shell replica thumbpicks too, available below, only at BanjoTeacher.com