Interior Tunnel Walls H0 Looking into a tunnel on a model railway layout, you will mainly see a black hole. The new Interior Tunnel Walls made of high-quality structured hard foam will give your layout a realistic touch. Thanks to this innovative product the interior wall of the tunnel is covered with stone like the original. The package contains a left-hand and a right-hand straight interior wall (ref. 58030) or a curved one (ref. 58031) with a length of each 3.94 in. The interior tunnel walls are suitable for catenary. The stone structure of the interior tunnel walls corresponds to the well-known NOCH hard foam series 'PROFI-plus Stone Wall'.