This loudspeaker module is suitable for models with gauge 0 or gauge 1. Its built-in passive radiator, in conjunction with the built-in broadband loudspeaker, provides good bass reproduction without neglecting the highs and mids. Especially for diesel or steam locomotives, this module is a real alternative for those who like deep bass. The speaker fits perfectly with our LokSound 5 L or LokSound 5 XL decoders.