Add a concrete tunnel portal over any HO scale track. Easy to color plaster castings. Meets NMRA specifications. Color with Earth Colors™ Liquid Pigment.
Outside: 5 3/8 in w x 4 7/8 in h (13.6 cm x 12.3 cm)
Inside: 2 11/16 in w x 3 11/16 in h (6.82 cm x 9.36 cm)