The cups and the warmers are a proprietary system. The cups themselves are approx. 3.5" in diameter and have a deep recessed on the bottom. It would take a cup with the exact same radius to fit in the warmer, without falling off the side. They would need to be the same diameter as well, in order to sit on the bulbous shaped burner. I have seen nothing like these cups before. But I bought enough melt cups for each of my warmers, threw out the wax in them, so I can melt whatever vendor wax I choose. I clean the cups out just as you would the plate in any other warmer. They are made of a high density plastic. The two yankee warmers that I have that hold these cups get in the range of 145-165 degrees. Not sure why but one of my warmers melts 20 degrees hotter than the other. Yes, I've put a thermometer to each of them to know this for sure.
