Kadee KDE309 Electro-Magnetic Undertrack Uncoupler
0A large electro-magnet designed to be mounted beneath the track. The magnet is arranged to create the correct field needed to correctly open Kadee couplers and place the knuckles in the uncouple delay position.
Once the knuckles are in a coupling delay position the tongue on to each each coupler prevents the knuckles from re-engaging and the train can be propelled clear of the magnet. Only when the train is finally separated do the knuckles re-centre, ready for coupling again.