Marklin 7251 Base plate 
This is Marklin 7251 Base plate in HO scale. 3 mm / 1/8" high. This base plate can be used only in conjunction with the 7250 base plate. Bridges and approach ramps bring the third dimension to a model railroad layout: from flatness to a sense of height. From the simple bridging of a road or river, to crossing several tracks, to realistically linking different levels on the layout - the Marklin accessory program offers the right solution for each task.