I have all the monorail sets made not counting the accessories like extra bogies. There were 3 sets – Futuron Monorail, Unitron Monorail, and Airport Monorail plus 2 add on track packs. This stuff is still in high demand by AFOLs and we wish they would make it again – though it does make those of us that have it have a very valuable collection! It was underproduced but perhaps it didn’t sell well back in the day.