This is Model #357, the third of my machined metal mechanical puzzles. It's made of T6061 aluminum, has a matte anodized black finish, 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. (But if you do lose any of the pieces, let me know and I'll sort it out.)
Warning: the internal pieces are small and could be a choking hazard for young children. I can't imagine a child opening the puzzle - it's pretty hard - but better safe than sorry so please keep the puzzle away from children under 5.
This is a limited edition of 200 puzzles and I've hand engraved each one with its serial number. I assemble each one by hand and test it multiple times. I also fill in the logo on the top of the puzzle with paint by hand (I think it looks cool!).