This listing is for a COMPLETE SET of our O gauge Timber Frame accessories. This set includes 2 Timber Frame Tunnel portals AND 2 Timber Frame retaining walls (one left and one right). The O Gauge 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. The O Gauge retaining walls measure 9" L X 8" H. Made from solid wood and finished in a light brown stain. All of our products are proudly Made in the USA! *TRAIN & ACCESSORIES NOT INCLUDED