Model #357 is the third in a series of machined metal mechanical puzzles made by Pyrigan & Co. It is a limited edition run of 200 puzzles and each one features a hand engraved serial number.
The goal is to completely disassemble and reassemble the puzzle. Designer John Partridge wanted the solver to be able to completely understand how and why the puzzle actually works. For this reason, he made it so that Model #357 comes apart entirely, and all the components can be laid bare. You will see that everything inside is included for a reason. A great puzzle for the curious mind!
Model No. 357 is made of T6061 aluminum and has a bead-blasted, matte anodized black finish. It weighs about 13 ounces, and measures about 2″ on a side. It has some fairly small internal pieces that may fall out and roll away once it is unlocked so you probably want to do the final disassembly over a tray.
Warning: the internal pieces are small and could be a choking hazard for young children.