Material: White Horn, Clear Horn, Black Horn & Buffalo Bone. Instrument: We recommend Bone Tones for Acoustic Guitar, Electric Guitar, Gypsy Jazz Guitar & Arch-top Jazz Guitar. Tone: Buffalo Bone is a hard material that has clear crisp clean tones. Buffalo Horn has the closest tone to the fabled Tortoise shell picks as it is made from the same material, Keratin. Although softer than Bone it is still very hard wearing and has a more rounded mellow tone. Design: Bone Tones are based upon the Classic 351 shape. They are typically 2.5mm thick chamfering down to a playing tip at 0.7mm thick. Contents: This Tin contains 1 of each of the Bone Tones Guitar Picks. Notes: Although we have tried to ensure that our photos represent the Guitar Pick that you will receive, there is a high level of variety in our picks due to the nature of many of our natural materials.