O-SCALE TIMBER FRAME SYSTEM features simulated rough-cut weathered timbers, antique wrought iron strapping cleats, and hand-forged threaded bolts. Ready to use. Cast in highly detailed urethane foam. Classic style for narrow gauge models. Outside dimensions: 8″ W x 8″ H x 1/2″ thick. Inside dimensions: 4-3/8″ wide by 6-1/2″ high. ATH-6110-O-Scale Low Post Timber Wall, ATH-6111-O-Scale High Post Timber Wall, ATH-6195-O-Scale Timber Frame Portal.