The magnetic circuit design of Turii is often used in speakers. The external magnetic circuit is very rare and too expensive for earphones. The built-in magnetic column opts high permeability material processed by CNC to form a structure that can give more magnetic density to the air gap position. The magnets used in the Turii unit are neodymium magnets with a natural magnetic density of 1.6T.
This may sound like a tesla unit to many people, but the difference is, the bearings used to support the suspension material are not integrated with the magnetic circuit. Instead, they are made of copper, which is basically non-magnetic, to eliminate the loss of the bearing structure to the magnetic field.