HO scale model trains are a significant part of model railroading history, and we can partially credit the overall popularity of model trains with the rise of a convenient, tabletop scale like HO.

Direct-current model with 21-pin connector, $214.99; with ESU LokSound V5 sound decoder, two cube-type speakers, and an ESU-designed “PowerPack” with two super capacitors, $324.99. Manufacturer: ...