No, there are different “brands” (like saying Kleenex when you mean tissue), and they come in all sizes and shapes. Some people like them. Some people don’t. I don’t know if any one “brand” is better than the other. I have a lot in my system and have never had any issues. I bought generic ones on AMAZON (the cheaper ones). When choosing them, always (as with any filter media) look for the ones with a lot of surface are, but that will allow a free-flow of water through the stack. Hope that helps.