933-3261 Modern Roundhouse Three Stall Add On KitThe Walthers Cornerstone 3 Stall Modern Roundhouse will be a hallmark of later steam era railroading on your layout. These add on stalls allow you to expand your Modern Roundhouse with additional stalls. Roundhouse size was based on the number of engines coming and going in any 24 hour period, with the busiest terminals requiring full circle roundhouses, so these extra stalls will allow you to match your roundhouse to your layout's needs. This