A magnetic coupling is a device that is capable of transmitting force through space without physical contact.  Attractive and repulsive magnetic forces are harnessed to perform work in either a linear or rotary fashion.  In its simplest form, a magnetic coupling is comprised of two components: a driver and a follower.

Linear Couplings
Tubular – these types of magnetic couplings are configured so that one member of the coupling is fully nested within the ID of the second member.  The two components share a common axis about which both translate.
Axial misalignment – Tolerant.
 Inherently, linear couplings align axially.  As such, any misalignment will lead to the driver pulling the follower into position.
Radial misalignment – Tolerant.
The amount of tolerance is based on the spacing between the driver and follower.  The larger the spacing, the greater the tolerance to radial misalignment.  Large radial offsets in closely spaced coupling may lead to excessive radial loads on bearings or shafts.
Angular misalignment – Tolerant
The amount of tolerance is based on the spacing between the driver and follower.  The larger the spacing, the greater the tolerance to angular misalignment.
Planar – these types of magnetic couplings are configured so that the magnetic flux is transferred about the flat end faces of the magnetic assembly.  The two components are attracted to one and other and typically require additional thrust bearing support for proper integration.
Planar (direction of motion) misalignment – Tolerant.
 Inherently, linear couplings align axially.  As such, any misalignment will lead to the driver pulling the follower into position.
Planar (perpendicular to direction of motion) misalignment – Very tolerant
Designs can be produced to constrain 2-DOF if required
Angular misalignment –Tolerant
The amount of angular misalignment depends on the air gap between the two members