This is a three-piece Miffy pajama set. I purchased it as a set from the store. All pieces are made of thin fabric of the same thickness. It includes both short-sleeved and long-sleeved tops, making it very convenient to use depending on the day! It's a great deal because it can be used year-round, except in the dead of winter. I hardly wore the long-sleeved top. I wore the pants for one season. I wore the short-sleeved top occasionally. The pants have a mark on the front, so you won't put them on backwards. It's a very cute set.