At the core of sealless mag drive pumps is the magnetic coupling. There are two assemblies that contain an equal number of magnets with alternating poles. The first, inner magnet assembly, connects directly to the pump shaft while the second outer magnet assembly is driven by the motor. The attraction of opposing polarity magnets align the inner and outer magnet assemblies, which in turn enables the rotating outer magnet to transmit its rotation to the inner magnet and pump shaft assembly. This then rotates the pump internals, creating flow.

A containment shell - called a canister - fits around the inner magnet, keeping the liquid inside the pump without the use of a dynamic seal.