With the invention of the NOS (New Old School) puzzle series, Gregory took the six piece burr format and turned it on its head. The only thing more noteworthy than the uniqueness of the series was how difficult they are to make.

Compressed is the first of the NOS designs. It's very tricky to disassemble and uses some rather extraordinary coordinate motion. Reassembly is also difficult, and has a mild dexterity component. Two sets of three identical pieces move in ways you just don't expect.