Thank you for viewing. This is a Mikihouse long undergarment. It's a set of 4! The size is 50. I used these in a rotation of 4 pieces for about 3 months, starting in May. I'm selling them because my child has outgrown them. Except for the star pattern on the 4th piece, there are no noticeable milk stains or dirt. Please check the photos if you are concerned about the condition. They have been home-cleaned, but these are used children's items and are subject to my own personal inspection. Please understand this before purchasing.