Usually it is a double fan (DF) but check the seller for details. Also the size of that DF can vary greatly. I would stay away from the mail order catalogs that sell everything. A Daylily farm/ hybridizer tends to increase your chance of a healthy, correctly named Daylily.
I only buy one DF as I want variety but some people are looking for a mass planting and may buy more than one.
Hope this helps. Lisa