Please be advised that we will be closed from December 30th to January 4th, and shipping will resume after that period. Mini Soroban (Abacus) - Ebony 17-digit / Bone Bead 15-digit It seems that bone bead sorobans may darken somewhat with age. Bone beads from Einpin are rarely seen these days. Also, ebony sorobans are expensive and may have a high rarity value. I think they are perfect for a collection. The longest one is 18.5 cm. Thank you for viewing.