LEGO Black Plate 2 x 3 with Rounded End and Pin Hole (3176) | Brick Owl - LEGO Marketplace
LEGO Train Coupling Plate with Red Magnet | Brick Owl - LEGO Marketplace
LEGO part 737ac04 - Red Plate, Modified 2 x 4 with Train Coupler Open for Magnet with Blue Magnet Coupling, Train - 8mm Cylinder (737a / x547a) at BrickScout