This piece converts an American Flyer body to scale operation. You'll need 2 -- see photo. You will have to drill and tap the circular center boss for the 2-56 truck mounting screw and you will have to trim the diagonal braces to fit. This is easily accomplished with a nail clipper or razor blade. Kadee 802 couplers may be fitted using either the holes in the center of the Kadee draft box or the holes on the side wings in which case the semi-circular bosses on the adapter are used and drilled to accept the Kadee screws. Leaving the lip on the Kadee cover will result in the coupler positioned slightly forward, or eliminate the lip and position the coupler draft box flush with the edge of the end sill for more prototypical appearance, however this can impede operation on tight curves.