For a tunnel that requires a double track portal, the Concrete Double fits perfectly over two N scale tracks. Color with Earth Colors™ Liquid Pigment. Set contains two pieces.
Outside: 3 15/16 in W x 2 1/2 in H (10 cm x 6.35 cm) each / Inside: 2 3/8 in W x 2 in H (6.03 cm x 5.08 cm) each