Try V-Picks. They are made in Nashville. They sell them at Carter Guitars. Very good picks. Not sure if those are the ones you are asking about but you should check them out.
Do you know what brand? The only ones I can think of that last insanely long are the bluechip picks. They are amazing. I use the TD 35 for guitar and the TPR 50 or 60 for mandolin. They have a webstore.
All I know is ,you can only get them at Carter's.
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