My question was for the originator of this thread as to what breed they need the feeders for.
As for using your feeders on any breed. No they are not usable for any breed. We raise Angoras ... metal would destroy the coat, catch the hair and pull it out of the rabbit. Also runs the possibility of injuring the animal in the process. They can get coat caught on anything that enters the cage. I have taken in resuces that were litterally stuck to something in the cage by a cord of wool... they had literally spun themselves to the item. Angora wool is very, very strong at this point. Any "wooled" breed (Angoras, Fuzzy lops, Jerseys, etc) should not use the feeder exhibited.
So, for the originator of the thread ... what breed of rabbit do you have?