The green knot revolves twice, making three full rotations along the way. It has a rectangular cross section and a triangular hole.
The blue knot revolves three times, making two full rotations along the way. It has a triangular cross section and a rectangular hole.
The two knots fit perfectly together, and only orbit each other by moving together.
Inspired by Oskar van Deventer's original Knotted Gear
The first few rotations of the knots will feel a bit rough, but once you gently rotate them ten to twenty times, they smooth out. Also, the knots rotate much easier in one direction than in the other.