I don't think I understand what you are asking about. I get Oxbow Timothy CUBES as treats... they are small, compact cubes of dried hay, about 1-2 inches square. They are sold in 1 pound bags, but I believe you can order them in larger amounts from Oxbow.
EDITED: Okay, I just noticed you had listed a link. I didn't see it previously.
This is what you are asking about:

Yes, I stand by my statement that hay "cakes" (also known as hay "cubes") should only be used as a treat and cannot be substituted for real hay. For one bunny, you could give a few a day, as long as the hay cubes don't prevent him from eating his regular hay.