This Kadee uncoupler magnet assembly is designed to be fitted beneath the track sleeper base with a steel plate to ensure that the magnetic effect will open the knuckles reliably.

Once the knuckles are opened the real Kadee magic comes into play, as the couplers will go into a coupling delay position. A tongue fitted to each each coupler prevents the knuckels from re-engaging and the train can be propelled clear of the magnet. Only when the train is finally separated do the knuckles recentre ready for coupling again.