Model Railroad O Gauge Timber Frame Tunnel Portals - Set of 2 O Gauge Timber Framed Tunnel Portals Measure 9 1/2 L by 9 1/2 H. Inside opening measurements are 5 1/2"W by 6 3/4"H. Completely Finished. Ready For Your Model railroad Layout. Works great for your Lionel, MTH, American Flyer trains Tunnel Entrance Side Retaining Walls Sold Separately: B004JKKHX2