I believe it was for regular size chickens. I found it on this thread... very bottom of page 1 with photo.The quail sized cup's might work out, but they probably would be for smaller bantam sized chicken's, I would think.
https://www.backyardchickens.com/th...-revolutionary-chicken.1530465/#post-25800381
I saw someone on here puts the quail cups on a 5 gallon bucket for their chickens.

