Owfeel 17 Columns Stainless Steel Frame Abacus Soroban Arithmetic Mathematic Calculating Education Tool Traditional and functional arithmetic abacus for calculation. 17 beads with 1 bead above and 4 beads below on each rod. Used as a classical calculator in office or a nice gift for abacus collectors etc. Great education tool for teacher and mathematic tool for children. Well made stainless steel frame, black/red beads.