Burr

IT
Jakub's Cube
Japanese Burr
Japanese Pagoda/ Crystal Puzzle 33 Pieces
Jeanne
Joy of Hex Puzzles
Kepler's Planetary Puzzle
Key Bunch
Key Trap (3D printed)
Kluvon
Knobula
Konstrukt
Krystal
Kubita
Kumi Six-Piece Set
Kumiki Desktop Puzzle
Kumikisaurus
L12 Burr
L8 Notchable