I am Sergej Abramenkov, inventor and designer of several mechanical puzzles, including the Binary Ring and Double Disk. I am pleased to offer a unique piece of engineering history from my personal design archive.This auction is for the Octogonzo — the Sole Factory Prototype of this configuration. This specific specimen is the only remaining factory-tooled record of this invention.HISTORICAL NOTE & INDEPENDENT INVENTION:This design represents a rare case of independent simultaneous inve...