This sleek, aerodynamic steamliner model, inspired by the design of the famous Union Pacific Big Boy, is a thing of beauty. A wind-up spring mechanism powers the train, and you can see the gear-wheel and flywheel turn from the top and side. 256 polished stainless steel pieces. On/off lever. For the experienced hobbyist, assembles with precision pliers (not included). No soldering or special tools required. Ages 14+. Model: 20" l x 3" h x 2½" d. Rails: 60¼" l x 1½" w x ¼" d.