Acoustic musicians have sought ultimate tone for as long as plectrums have been used. The premium ToneSlabs Tweener Three Round combination of hardness, rigidity, density, design and top shelf bevel techniques exceeds the tonal qualities of historically-prized, endangered tortoiseshell. ToneSlabs are the key to volume, clarity, and note separation. That's what all discerning musicians strive for, isn't it? Your quest for perfect tone has finally ended. ToneSlabs flatpicks are ideal for mandolin and guitar.