Two Brass Monkeys

Tetrahedrane

Tetrahedrane is a metal puzzle with four brass ends and six metal rods screwed into them, making the shape of the hypothetical tetrahedrane molecule. In order to assemble the puzzle, all rods need to be turned simultaneously and all of the left- and right-handed helical threads should be aligned.
https://twobrassmonkeys.com/pages/tetrahedrane

Hyperboloid burr puzzle

Hyperboloid is an assembly puzzle, produced by The Two Brass Monkeys. The puzzle started as a semi-classic burr puzzle with six pieces. When producing a wooden version for the International Puzzle Party, Naoaki Takashima discovered that a seventh piece could be added, while still fitting in a cubic box. The brass version was produced with micron accuracy.